In response, we’ve created a video that is our best response to the question. It’s long but comprehensive. It’s not just learning how to look at features, but addresses topics that cause confusion and cognitive bias that can really get in the way when seriously trying to learn to identify rattlesnakes. This video will walk you through the best way look at key features with a logical approach to differentiate between Mojave Rattlesnakes and Western Diamondback Rattlesnake.
What can you do? “Count the scales on the head”, someone says … but how useful is that in real-life situations? “Tail bands look different”, another comment will read … compared to what? There are thousands of photographs of both species online, but telling the difference between a Mojave Rattlesnake and a Western Diamondback Rattlesnake is still a point of confusion.
Build your skills to identify a Mojave Rattlesnake vs Western Diamondback Rattlesnake
A rattlesnake in the backyard is one thing … but how about in the house, in the bedroom, and even under the bed? It happens, though, thankfully very rarely.
The thing is: rattlesnakes don’t want to be in your home. There are species of snakes that get in often, daily even, like Nightsakes and baby Longnosed snakes. Rattlesnakes, on the otherhand, for one reason or another just don’t make an effort to come inside. If I were to assume, based on how rattlesnakes handle stress and modify their behavior accordingly, the activity inside a home makes them less than ideal hiding spots.
How often does a rattlesnake get inside?
Fortunately, Rattlesnake Solutions has a very large collection of human-conflict data of this sort from over ten thousand individual encounters. It happens, but not very often.
Of all encounters we’ve documented, fewer than 100 were rattlesnakes inside the home. If you remove homes that were previously abandoned, missing entire walls, or in a condition where they should be condemned … you end up with fewer than 40. That puts the chances of a rattlesnake encounter in your home, based on snake removal records, at 0.4%. That puts it into a solid “don’t worry about it and go on with your day” category.
Most of the time, a call to catch a rattlesnake inside a home ends up with a Desert Nightsnake in our bucket. These little guys look quite a bit like a rattlesnake and are often mistaken for them.
How does a rattlesnake get into the house?
Fortunately, rattlesnakes are easy to keep out of the house. They come in the same way we do – right through the front door. Most of the time, a rattlesnake inside a house, and in fact a good portion of the other types of snakes as well, come in through a door left open.
Who leaves the door open in Arizona? Everyone, it seems, on the right cool day. Especially our midwestern friends, where it seems an open backdoor on a breezy spring day is a normal thing, tend to leave that sliding door open a bit during prime rattlesnake activity time.
On other relocation calls where we’ve captured rattlesnakes inside the home, the situation is often similar. A home with a wall partially removed during construction, a partially-completed vent removal allowing access, large gaps under garage doors or patio doors, etc. Simply, if there is access to inside the home, animals may find their way in.
What’s going on with this photo of the rattlesnake under a bed?
This photo was from an apartment complex in the North Phoenix, Cave Creek area. Mitch ran out to capture it. Upon arriving, he assumed it would be another nightsnake (which it often is) and had to run back out to the car to get his tongs and bucket after seeing this.
He was able to quickly and safely capture it. But how and why was it in there? And does the resident need to worry about more of them?
As we described earlier, it turns out that the resident left the home for less than 5 minutes, leaving the door slightly ajar. That’s all the time it takes for a wandering rattlesnake to find the cool, air conditioned “cave”, and slip inside.
This also does not mean there are others. Rattlesnakes, while being quite social in a variety of situations, are most often found at homes alone. They do not, as a popular myth goes, travel in pairs.
This also does not indicate that there are more rattlesnake encounters in the Cave Creek area … that is just true, regardless of this particular encounter.
How to keep rattlesnakes out of the house?
The best way to keep rattlesnakes out of your home is to keep doors closed and eliminate access, down to a 1/4″ space.
Sometimes that can be tricky, however. Something we have seen with homes in the valley is an issue with how cabinets are put together. This seems to be the reason behind a majority of nightsnake visits, and at least a few rattlesnakes.
If you look under the sink in your kitchen or bathroom, you’ll most likely see the pipes disappearing into the wall in an orderly, well-sealed way. Behind the cabinets, though, is a different story. The pipes coming into the home may be unsealed. That means if there are any gaps under the cabinet overhang (there most often are), there’s a direct highway from under the home to your bedroom bathroom. This may also be the cause for your scorpion and rodent issues.
The easy fix? Seal the gaps under the cabinet overhang. You could go through the trouble to pull out the whole cabinet, but without knowing for sure there’s a problem to begin with, that’s probably overkill. A Saturday afternoon with some expanding foam is all you likely need.
The other thing you should do is to take steps to reduce the overall number of rattlesnakes visiting your property. That is best done by a combination of property modification (landscaping, etc., here’s our step-by-step guide) and physical barriers, like properly sealed garage doors and rattlesnake fence installation.
So rest easy. While a rattlesnake inside the home is something that does happen from time to time, it’s nothing to be overly concerned with. No need to call the realtor or burn the house down; just keep the door closed and you’ll be just fine.
Better late than never – rattlesnakes are giving birth, even without the rain. One of the services we offer are serial property inspections, to continuously monitor properties to evaluate possible rattlesnake activity and provide recommendations to landscapers, pest control, and property managers.
We have been inspecting this particular property for many years, and this is the most interesting thing found there to date.
On the previous inspection, Greyson noted a shed skin in an area at the edge of the property. Knowing a fresh shed during this hot and dry period could indicate an estivation den nearby, he focused on that spot during his visit yesterday, and, whoa.
Here is what was found: a late-season estivation den with a mixed bag of Western Diamondback Rattlesnakes, with one having given birth in the recent past, and another in a deep blue phase (preparing to shed skin)
While this is not entirely unusual, what is different about this year is that we are seeing that rattlesnakes are having their babies later than usual, and they are doing so in their estivation dens instead of moving to their usually-preferred birthing spots.
This is likely a response to our exceptionally hot (the hottest on record) summer and near-complete lack of rain. This is similar to a recent visit to a home by Dave in Tucson (I’ll be posting this shortly as well) where he captured a total of 14 rattlesnakes.
Are rattlesnakes giving birth later this year than normal?
According to our observations and activity on the relocation hotline: yes, it appears that rattlesnakes are having babies later this year than usual. In a normal year, we start to receive our first calls to capture groups of mother Western Diamondback Rattlesnakes with their newborn babies in early July, usually hitting its peak around the first week of August, then trickling in here or there until around the first week of September. This year, it took much longer for this to be normal, only now (mid-August) has it become routine.
Likewise, rattlesnakes seen in informal surveys and in our study of rattlesnakes in the Phoenix Mountain Preserve have shown that Western Diamondback Rattlesnake and Tiger Rattlesnakes that would have likely given birth by now are still languishing in a gravid (pregnant) state at estivation dens.
While this is in no way a full representation of what’s happening out there, but does represent 10 years of data collection and informal survey observations. It should also be noted that while this is the case in the Phoenix and Tucson areas, it is unlikely to represent behavior in other regions.
Why are baby rattlesnakes being born later this year than usual?
This year makes that a little bit tougher than normal. If monsoon rain triggers pregnant rattlesnakes to give birth, what happens when there is no rain at all?
They have to give birth eventually … so what we are seeing is this: The mother rattlesnakes are staying at estivation sites (spots selected to hide away during the hottest summer months) far longer than they normally would. Rather than moving to a birthing site as they normally would, they are having their babies right in place.
This likely isn’t good for the babies, ultimately and unfortunately. They lose moisture more than twice as quickly as adults (J. Agugliaro, H. Reinert 2005). Unless we get some rain soon, that could be big trouble for this year’s babies. We’re hoping for the best, but looking at the forecast … hoping is all there is to do.
How homeowners can keep baby rattlesnakes out of the yard
Keeping the smallest rattlesnakes out of your area is a bit different than the larger ones.
First, the space they need to get in is much smaller … anything more than about a third of an inch can allow access. Second, they make frequent movements and may not necessarily know where they’re going. Unlike adults, who’ve had a lifetime to map out a homerange, babies may show up any place, any time. For that reason, physical barriers are the best bet. Rather than go too far into detail here, I’ll refer you to our guide to keep baby rattlesnakes out of the yard.
Schuett, G.W., Repp, R.A., Hoss, S.K. and Herrmann, H.‐W. (2013), Parturition in a Desert Rattlesnake. Biol J Linn Soc Lond, 110: 866-877. doi:10.1111/bij.12166
Agugliaro J, Reinert HK. Comparative skin permeability of neonatal and adult timber rattlesnakes (Crotalus horridus). Comp Biochem Physiol A Mol Integr Physiol. 2005;141(1):70-75. doi:10.1016/j.cbpb.2005.04.002
There’s no better first post topic for our new blog, perhaps, than one highlighting the most commonly removed snake species in the city. They’re also one of the most iconic animals in the American West: The Western Diamondback Rattlesnake.
The Western Diamondback Rattlesnake is, as far as rattlesnakes go, a generalist. It can live in a wide variety of habitat and climates. In Arizona, this means any area where the city borders native Sonoran Desert habitat is also likely a resource for the Western Diamondback. Especially in areas North of the 101 in Scottsdale and Phoenix, where landscaping is a mix of native desert features and plants, rattlesnakes make their home.
We’ve relocated Western Diamondbacks from almost everywhere in the city at one time or another. Some of them, like those that show up in the center of the city, get there by hitchhiking in vehicles or landscaping materials. Some are intentionally captured and brought there by people that think that a rattlesnake would be a great pet, and released once they realize how wrong they were! For the most part, Western Diamondback Rattlesnakes are limited to areas that come into direct contact with native desert.
How big does the Western Diamondback Rattlesnake get?
In the Phoenix area, a very large Western Diamondback Rattlesnake is about 4 feet long, with most reaching a slightly smaller adult size in the 3.5′ range. While some individuals may get into the 5′ range, it is very rare. In fact, in over a thousand rattlesnakes captured and relocated by Rattlesnake Solutions over the years, only one even got close, at an estimated 4’10”. It does happen, but to say “diamondbacks get 5′ long” is a lot like saying “an adult human is 7′ tall. It happens, but it’s not common, and generally not useful when discussing size. Things especially fall apart when a person claiming to see a 6′ diamondback also claims to see them often.
What is most likely, is that people just aren’t as great at estimating size of objects as we like to believe we are, combined with just how bad our memories actually are with remembering the details. If you want to do a simple experiment, get a 4′ (or so) stretch of rope or hose, and coil it in the bushes in the backyard. Ask someone to come out, without telling them why, and tell them to give you the size from 10′ away. If you get any answer that isn’t “how am I supposed to know, I’m not a tape measure!”, it likely won’t be anywhere near the actual size.
While there are some reports of Western Diamondback Rattlesnakes getting very large (over 7′ long), this is very rare, and even more rare here in Arizona. Diamondbacks found in the Eastern part of their range in Texas tend to get larger, in-part due to having larger prey to eat, and more of it. There are also genetic differences between these populations, with Diamondbacks East of the continental divide area (about the Arizona/New Mexico border) that may make our Western, Western Diamondbacks end up on the small end. Even more confusingly, there is a completely different species, called an Eastern Diamondback Rattlesnake, that does not live in Arizona at all, and gets larger than any other species of rattlesnake. All of this can cause some confusion when someone says, “hey, I saw a 6 foot diamondback!”, and tries to do some fact-checking on Google.
What part of the City has the most Western Diamondback Rattlesnakes?
Scottsdale 🙂 That’s an easy one. By looking at our relocation data over the years, the corridor above the 101, West to about the 51, has the highest rate of rattlesnake encounters. This isn’t just because of location – it’s more about what is there. Mostly new-ish developments, continued development, and natural landscaping contribute to wildlife encounters here. This doesn’t mean that if you live in North Scottsdale, you’re destined to meet a rattlesnake. … If your yard is within about a block of native desert habitat, however, it’s likely.
Further into the city, your odds of running into a diamondback are much lower. Even on mountains where other species of rattlesnake are fairly common, like Camelback Mountain or Mummy Mountain, diamondbacks have more or less been killed off by surrounding traffic and development.
“I’ve seen Western Diamondbacks … are those different than coontail rattlesnakes?”
This is a question we get from time to time, and no, they are the same species. Western Diamondbacks have a characteristic black and white banded tail just before the rattle. This can be used to identify them, and tell the difference between them and other species of rattlesnake.
Western Diamondback Rattlesnakes are also a great example of some of the confusion that comes from common names given to animals. It seems that almost every place in the Western United States has something that the locals will call a “diamondback”, though in reality there is only one Western Diamondback, Crotalus atrox, which lives in the Southern half of Arizona, Southeastern California, and East into Oklahoma and Arkansas. In much of Utah, Idaho, and Wyoming, locals may refer to the local “diamondbacks”, but the rattlesnakes that live there are actually Prairie Rattlesnakes or Great Basin Rattlesnakes.
They are also often mistaken for Mojave Rattlesnakes. Usually the mistaken identity is given to the diamondback, due to the Mojave’s more famous reputation for being overly ‘aggressive’.
Here are more photos of wild diamondbacks! For as common as they are, I never tire of seeing them. If you’ve seen any, tell us about it in the comments.