The fastest way to get rid of snakes in your basement is to remove them with a trap or professional help, then seal every opening larger than a quarter inch in your foundation to keep them from coming back. Snakes don’t move into basements randomly. They follow prey, usually mice or rats, into dark, cool spaces through surprisingly small gaps. Solving the problem permanently means addressing all three factors: the snake itself, the entry points, and whatever attracted it in the first place.
Why Snakes End Up in Basements
Snakes go where food is. Any structure that houses small rodents is attractive to the snakes that prey on them. If you have mice in or around your basement, you’ve essentially set a dinner table. Basements also offer exactly what snakes look for in shelter: cool temperatures, darkness, dampness, and minimal disturbance. A snake that finds both food and cover has no reason to leave.
They get in through foundation cracks, gaps around pipes and wiring, unsealed dryer vents, and spaces under doors. Snakes can squeeze through any opening a quarter inch or larger. If a mouse can fit through a gap, a snake can follow it. Older homes with settling foundations, crumbling mortar, or unscreened crawl space vents are especially vulnerable.
Identify the Snake Before You Act
Most snakes found in basements are harmless species like rat snakes, garter snakes, or ring-necked snakes that wandered in after prey. But identification matters because it changes how you should handle the situation. Keep your distance and observe.
Venomous snakes in North America are almost all pit vipers (copperheads, rattlesnakes, cottonmouths), and they share a few reliable features. They tend to have thick, stocky bodies relative to their length, triangular or spade-shaped heads, and vertical, cat-like pupils rather than round ones. They also have a small pit, like an extra nostril, on each side of the head between the eye and nostril. Young copperheads and cottonmouths have a distinctive bright yellow or greenish-yellow tail tip. Nonvenomous species are typically more slender, with round pupils and narrower heads.
If you can’t identify the snake or suspect it’s venomous, don’t attempt removal yourself. Back away and call a wildlife removal professional.
How to Remove a Snake Safely
For a nonvenomous snake you’ve positively identified, you have a few options. The simplest is to open a basement door or window to the outside, block off escape routes deeper into the house, and give the snake a clear path out. Snakes don’t want to be in your living space any more than you want them there.
If the snake won’t leave on its own, glue-based traps are the most widely used method. Place them along walls, in dark corners, or near spots where you’ve seen the snake. Basements are ideal trap locations since snakes gravitate toward cold, dark, damp areas. Once a snake crosses the adhesive strip, it gets stuck and can’t move.
When you find a snake on a glue trap, don’t try to pull it off. That risks injuring the snake and provoking a bite. Instead, take the entire trap outside to a release location and pour vegetable oil generously over the snake and the glue pad. The oil neutralizes the adhesive, and the snake will detach itself and crawl away unharmed. This makes glue traps effectively a catch-and-release method.
You can also use a large bucket or trash can. Place it on its side near the snake and use a broom to gently guide the snake inside, then tip the bucket upright, cover it, and carry it outside. Release the snake at least a few hundred yards from your home in a natural area with ground cover.
Skip the Mothballs and Repellents
Mothballs, sulfur, and commercial snake repellents (which are usually just combinations of naphthalene and sulfur) do not work. Research from the University of Nebraska tested naphthalene crystals, sulfur, and a commercial blend of both on garter snakes. In familiar habitats, 90% of snakes exposed to sulfur showed no avoidance at all. In unfamiliar habitats, nearly 78% of snakes crossed directly over the repellent strips without hesitation. None of the substances produced statistically significant avoidance behavior compared to the control group.
The researchers found that a snake’s drive to seek cover, follow prey, or explore an area consistently overrode any deterrent effect from the chemicals. Over time, snakes may even habituate to the smell and associate it with their home range. Worse, mothballs contain naphthalene, which is toxic to humans and pets when used in unventilated spaces like basements. Save your money and skip this step entirely.
Seal Every Entry Point
Removing the snake without sealing your foundation just means another one will find its way in. Walk the full perimeter of your home and inspect every inch of the foundation, especially where pipes, wires, and utility lines enter the building.
Close all openings larger than a quarter inch. For cracks in concrete, use epoxy or mortar. For gaps around pipes and wiring, use expanding foam sealant stuffed with copper or stainless steel mesh (regular steel wool rusts and disintegrates). Copper mesh won’t corrode and adds a physical barrier that snakes and rodents can’t push through. For larger openings like crawl space vents or basement windows, install quarter-inch hardware cloth, which is a rigid wire mesh with openings too small for snakes or mice to pass through. Half-inch mesh works for larger snakes but won’t stop juvenile snakes or the mice they follow.
Don’t forget to check door sweeps on basement doors, window well covers, dryer and exhaust vents, and any gaps where the sill plate meets the foundation. Use latex caulk for openings a quarter inch or smaller and elastomeric sealant for anything larger that needs flexibility as your house shifts with the seasons.
Eliminate What Attracts Them
Sealing entry points is only half the equation. You need to remove the reason snakes came to your property in the first place, which almost always means dealing with a rodent problem.
Start inside. If you have mice in your basement, set traps and address how they’re getting in (the same gaps that admit snakes). Store pet food and birdseed in airtight containers. If you have bird feeders near the house, consider removing them temporarily, since fallen seed draws rodents, and rodents draw snakes.
Outside, the goal is to eliminate cover and habitat within about 30 feet of your foundation. Keep your lawn mowed short. Move firewood piles, rock piles, stacked bricks, garden pots, and dense ground-level plants away from the house. Snakes use all of these as shelter, and rodents nest in them. Dense shrubs planted against the foundation are a highway for both snakes and their prey. Trim vegetation so there’s a clear buffer of short grass or gravel between your landscaping and the house walls.
When to Call a Professional
Hire a licensed wildlife removal service if you find a venomous snake, if you’re seeing snakes repeatedly (which suggests an established entry route or rodent colony), or if the snake is in a spot you can’t safely reach. Basement removal typically costs $200 to $300 for a nonvenomous snake and $250 to $600 for a venomous one. Emergency or after-hours calls add $100 to $300 on top of that.
Most removals take a few hours, though complex situations may require trap checks over several days. Many wildlife companies also offer exclusion services, where they inspect and seal your entire foundation, for $200 to $600 or more depending on the size of your home and the number of gaps. If you’re dealing with recurring snakes, this service often pays for itself by solving the problem once rather than paying for repeated removals. Some states have legal protections for certain snake species, so a licensed professional ensures the removal complies with local wildlife regulations.
Preventing Future Problems
Once you’ve removed the snake and sealed your foundation, maintain those defenses. Recheck your foundation seals every spring before snakes become active and again in fall when they start seeking warm shelter. Expanding foam degrades in sunlight and can shrink over time, so inspect it annually. Keep rodent control ongoing, since a mouse problem you ignore will eventually become a snake problem you can’t ignore. A basement that offers nothing to eat and no way in won’t attract snakes, regardless of what species live in your area.