The rumors are out there, and it’s true! Rattlesnake encounters spike in October, and it’s happening right now throughout much of the state. But, this is completely normal, happens every year, and it’s not really anything to worry about. Let’s take a look at the reasons, and why you shouldn’t be too concerned.
If you haven’t been outside yet this morning: it’s cold!
Rattlesnakes don’t have sweatpants and blankets, so they have work to do to avoid it. That means there’s a lot of activity in October, especially in the late afternoon and just after dark. They’re making movements to wherever they’re going to spend the winter … and it just so happens that this occurs right when people spend more time outside enjoying the cooler weather.
More people moving at the same time that more snakes are moving = more snake encounters. This is normal, and happens every year Add in a continued hockey-stick upward graph of population and development, and you have record encounter figures.And no, there is not, as I’ve seen a few post out there, a “bumper crop” of rattlesnakes.
They don’t spring forth from the Earth when water touches it. It would take several years of consecutively prime conditions to result in both higher birth rates and survivorship of young that could show a measurable increase in the rattlesnake population. Even then, their natural predators (every animal with a pulse in the desert) would put it right back where it should be.
The rumor mill is abuzz (see what I did there?)
I am fortunate that the local news allows me to comment on these kinds of rumors, and put it into perspective. Rumors like this can be problematic, and lead to dangerous situations for people and snakes. A person can have a totally normal experience, like seeing two rattlesnakes on a single bike ride, and then remember hearing from old Larry at the feed store that there’s a gull durn rattler invasion happening. That person might then take that typical experience of seeing multiple rattlesnakes and incorrectly use it to confirm Larry’s herpetological theories. Then come further posts, some causing people to do things like kill snakes to “help”, putting themselves in danger in the process.
Now that we know all of this, check out this video from KOLD in Tucson that explains.
More information on that snake fencing mentioned in the article:
Now that evening temperatures are in the 50s for most of the major metro areas of Arizona, with cooler temperatures on the way, rattlesnake behavior shifts yet again. Throughout October into early November, rattlesnakes are on the move, eventually settling into their chosen winter den. For many homes, this den can be the garage.
This is also when many of our seasonal residents (aka snowbirds) fly back to their winter Arizona homes to wait out the snow in our perfect weather. If this is you, you may want to pay special attention.
Why do rattlesnakes go into garages?
Rattlesnakes go into garages for a simple reason: to them, it’s just a cave. Not just any cave, but one that’s slightly warmer than the surrounding areas due to the proximity to a larger, heated cave (your home). This cave is also loaded with golf clubs, various boxes of holiday decorations, and dozens of boxes mentally labeled “stuff I’ll deal with later”. When there’s easy access, why wouldn’t a snake use it for a winter den?
How do I keep rattlesnakes out of my garage?
Fortunately, this is relatively easy – it just takes some attention at the right time. That time, as you might imagine, is right now.
The biggest single thing you can fix is won’t cost you a thing, because it’s a behavior change. That is: keep the garage closed as much as possible. Yes, the temperatures are perfect right now and it’s the ideal time to pull those Christmas decorations out even though it’s barely October and the HOA will throw a fit: keep it closed unless you are actively coming and going from the garage. During the early evening and just after dark, rattlesnakes are very actively moving, and if you accidentally leave the door open, even just a little, you’re all but inviting them in.
You can also check the seal on the garage door to see if it’s doing the job. What’s the easiest way to tell? Look at inside corners on either side of the garage door. If you see leaves and debris blown in from outside: congratulations, your door seal is bad. Or you can just look at it (this is the rubber bumper that comes in contact with the garage floor). If it’s frayed, rodent-chewed, or missing the edges so that it doesn’t come into perfect contact with the floor, your favorite garage door company should be called to be replace it. The best part? You’ll not only not see a rattlesnake in there this year, but fewer scorpions and other stuff, too.
Last of the big things to do: clean up the garage. I know, it’s been on the list for years, but if the possibility of a rattlesnake in the garage isn’t a motivator, what is? Rattlesnakes want to stay in a den where they can rest without disturbance, meaning that they need places to hide. A garage with no places to hide is not useable, so let’s do that. That doesn’t mean you need to clear it out, just arrange it differently. Replace old cardboard with plastic storage boxes (with lids), stored right on the ground, without space in between. Pull everything away from the wall a bit, and create space wherever possible.
Things you can do to keep rattlesnakes out of the garage:
Keep the garage door closed as much as possible, never leaving it open after dark.
Check and replace, if needed, the rubber seal at the base of the garage door.
Re-organize items stored in the garage to eliminate as many hiding places as possible and create space.
Move stored items away from walls 10+ and avoid loosely-placed items, especially in corners.
Have your garage and property inspected by a professional to get insight on specific features that should be addressed, and look for signs of resident rattlesnakes.
Avoid using products like poisons, glue traps, and snake-repellents (these don’t work and give false peace of mind – you want to remain aware)
How can I tell if a rattlesnake is already in the garage?
Here’s an easy trick we’ve learned over the years to tell if a rattlesnake is using the garage, even if it’s hidden somewhere in the back, with relative accuracy. Check the corners! Rattlesnakes don’t just crawl into the back of the garage and stay put – there is actually quite a bit of lateral movement. This staging behavior often puts rattlesnakes in the corners nearest to the garage door. Even if temporarily, this can leave distinctive tracks that can indicate whether or not a rattlesnake may be elsewhere in the garage.
In every garage, these corners have dust, leaves, and various stuff. This dust is very useful – a rattlesnake will leave a circular print in the corner, pushing larger debris to the edge. If you see this pattern, it could mean that a rattlesnake has either visited the garage recently or is still in there. If you see it between November and February, the odds of a rattlesnake visitor are higher.
How long are rattlesnakes in garages?
Though we can find rattlesnakes in garages all year, typically this period of cool weather that the rest of the world calls “winter” is when it happens. You can expect that rattlesnakes will be where they intend to spend the winter by about the second week of November. Rattlesnakes will start to explore and make small movements outside by late February, through early March. By April 1, it’s most likely that any rattlesnakes hiding in the garage over the winter have gone out to do all the stuff they do in the spring.
What about the rest of the yard? How do I keep rattlesnakes away?
You may notice that our social media feeds are still full of rattlesnake captures and relocations, even in the coolest months of the year. Be assured: yes, rattlesnakes are hibernating (or brumating if you prefer) in the winter, roughly from November through February. However, as we’ve explained in previous winters, they can still be found from time to time on the surface.
The biggest reason you’ll still see so much from us is because we meter our content so that we don’t blow you away with 20+ posts during the summer days, and make you think we’ve disappeared during the winter. Every call is unique and interesting, with lessons and experiences that should be shared, so we space it out. That means that many of the photos you’re seeing in the winter may have been from calls we ran in October, etc.
There are of course snakes that are still active during the winter, both by their own choice, and not. We cover some of the reasons you may see one at your house during the cooler months in a previous post, named after the most common comment we see on photos of snakes found in the cooler months. “I thought they were hibernating!“
Why would rattlesnakes be active when it’s so old outside?
One of the biggest misconceptions about rattlesnake behavior is that they are driven purely by warm temperatures. While it is true that rattlesnakes, like all reptiles, are cold-blooded and depend on external forces to get warm, temperature is just one of many factors that determine whether or not they’ll become active.
Here’s a great example that happened recently. In 2020, the Phoenix area broke several records for the hottest, driest summer in recent history. When rain finally came to the valley after more than 100 days without a drop, it was on a cold December day.
With temperatures barely breaking 50˚F, why would rattlesnakes suddenly become active? Simply: they have to, or risk death. With minimal effort, I was able to find 7 Western Diamondback Rattlesnakes on the surface hoping for rain. The first was found at just 45˚F, and the last at 51˚F. Comparing field notes for the day with a couple of knowledgeable friends, who also knew to put on boots instead of sweatpants for the day, showed similar results. Rattlesnakes, even in relatively cold temperatures, were very active. When rain fell again for a brief period on Christmas day, again, it was not difficult to find a lone Western Diamondback Rattlesnake coming out for a drink.
Just because we see rattlesnakes in the winter doesn’t mean you will.
People are often surprised that we are still able to find rattlesnakes in the winter – in fact it’s probably why you’re reading this right now. If you’re not someone that wants to run into them out there, don’t worry: it’s very unlikely that you will.
Rattlesnakes that we find in the winter aren’t in the same situation that you’d find them during other, warmer periods. They’re not out moving large distances, tracking prey, looking for mates, or any of the other behaviors that most often result in an encounter. This activity is much more specific – just coming to the surface of their den, and back down again when they’ve gotten what they need. That means that if you’re hiking on a trail and not purposefully searching situations that seem likely to house rattlesnakes over the winter, you’re not likely to see them at all.
It’s December, it’s cold (for Arizona), and the Rattlesnake Solutions relocation team is still busy. Instead of picking up rattlesnakes from patios and porches, we’re pulling Western Diamondbacks from garages and sheds. Whenever this happens, a common comment pops up – “why are there still rattlesnakes out there? It’s Winter, I thought they were hibernating?” What is going on?
The answer is easy enough – why aren’t rattlesnakes hibernating? (or brumating, as is more accurate, with a note on that later) They are, and the places we catch them are where they’re doing it. As we have covered in previous articles about just how and why rattlesnakes choose garages as prime den real estate, rattlesnakes in the warmer parts of Arizona tend to have quite a few options for a survivable winter refuge. When a rattlesnake is found in a garage on a cold December day, it’s likely been there since October, and where it is found is where it was brumating. This is not the same as being active, being “awake”, or any situation where an imagined extension of rattlesnake activity has been extended because of a few warm days or any other reason.
“If it’s cold why are rattlesnakes still out?”
They’re not, they’re in, and that’s where you found them.
These cold-weather sleepy rattlesnakes are often discoveries by people using the holiday downtime to get to long-neglected projects, like cleaning out the garage or tearing down the old shed in the yard. Another common one throughout December are rattlesnakes found under boxes of Christmas trees and other holiday decorations that have remained untouched in the deepest corner of the garage for 11 months. These discoveries are small rattlesnake dens, of only one or a handful of individuals,
Here is a trio of Western Diamondback Rattlesnakes that I captured in a storage closet at an apartment complex in Cave Creek:
“But I saw a rattlesnake outside! Why isn’t it hibernating?”
As mentioned earlier, rattlesnakes don’t truly hibernate. Rather, they do something similar called brumation. This means they’re sleeping a lot and avoiding the cold, but if conditions are good for them, they may come sit at the entrance of their den and hang out or move around a bit. What conditions cause this to happen vary by species and location. Here in the Sonoran Desert, temperates can get chilly but not often dangerously cold, and moisture loss is a concern. They don’t necessarily choose sites that have a lot of sun exposure, or even avoid it altogether (Hamilton et al 2008). On some warm days, especially just before or after rain, or a bit of sun after a some winter sprinkles, rattlesnakes will often come to the surface to take advantage of it. That means that if you see a rattlesnake coiled in the backyard, it’s likely been in the area for quite awhile already, and is just coming out a short distance.
“I heard on the local news that rattlesnakes are coming out early, or are active longer this year because of the weather!”
There is no evidence to suggest this is happening, but somehow it’s still a news story each year. According to our call logs over the past decade, our observations, and other research, rattlesnakes are going into brumation (ingress) and coming out of it (egress) in about the same times as normal. That is, generally, in by the first of November, and out by the 15th of March. That means that the shoulder times around those dates are full of rattlesnakes moving around and traveling, so sightings may increase, even as general activity is considerably less than other times of year. This is when you should be keeping garages and gates closed.
How can I be rattlesnake-safe this Winter?
Refer to some earlier articles we’ve provided about rattlesnakes during the cooler months: