A garter snake in your house is harmless. These small, non-venomous snakes are among the most common species to end up indoors, typically because they followed a mouse, sought warmth, or slipped through a crack they happened to find. You don’t need to panic, but you do need to get it out and figure out how it got in.
How to Confirm It’s a Garter Snake
Garter snakes are medium-sized, usually 18 to 26 inches long, with three light-colored stripes running the length of their body against a brown, tan, or olive background. Some have red or orange pigment showing through on the sides, and others display a checkered pattern between the stripes. Their belly often has two rows of dark spots. One easy tell: a red tongue with a black tip.
If what you’re looking at matches that description, you’re dealing with one of the most widespread and least dangerous snakes in North America. Garter snakes can look similar to ribbon snakes, which are also harmless. They look nothing like copperheads or other venomous species, which have thick bodies, triangular heads, and banded or blotched patterns rather than lengthwise stripes.
Why It’s in Your House
Garter snakes don’t enter homes on purpose. They end up inside for a few predictable reasons.
The most common is prey. Snakes follow mice and other small rodents through the same gaps those rodents use to get into your basement or crawl space. After eating, the snake will usually leave on its own if it can find its way out. If it can’t, it stays. A garter snake stuck in your basement is often a sign you also have a rodent problem, which is worth addressing on its own.
Temperature is the other big driver. In fall, garter snakes seek out spaces below the frost line to survive winter in a dormant state called brumation. Basements, crawl spaces, and foundation walls can mimic the underground crevices they naturally use. They’re often the first snake to emerge in spring, sometimes while snow is still on the ground, and they return to the same wintering spots each fall. If a garter snake finds your basement suitable, it may come back year after year, and it may not come alone. Garter snakes sometimes overwinter in groups.
What to Do Right Now
If the snake is in an open area, the simplest method is to place a large bucket or wastebasket over it, slide a piece of cardboard underneath, and carry the whole thing outside. Release it in your yard or a nearby area with ground cover. Garter snakes are slow and non-aggressive, so this is easier than it sounds.
If it’s hiding behind an appliance or in a cluttered corner, you can try placing a damp towel on the floor nearby. Snakes are drawn to the moisture and cover, and you may find it curled under the towel later. Another option is to set a glue trap along the wall where you last saw it. If you use a glue trap, pour vegetable oil over the snake and trap once it’s caught to release the snake unharmed.
If you’d rather not handle it yourself, most local animal control offices or wildlife removal services will pick up a snake from your home. Some will do this for free since garter snakes are non-venomous and common.
Are Garter Snakes Dangerous?
No. Garter snakes are classified as non-venomous to humans. A bite from one, which is uncommon and only happens if the snake feels cornered, causes nothing more than mild swelling, minor bleeding, and some redness at the site. Clean it with soap and water, cover it with a bandage, and watch for signs of infection like increased swelling or pus. That’s the full extent of treatment.
They pose no real threat to cats or dogs either. A pet might get a small bite if it harasses the snake, but the result is the same: minor irritation, nothing requiring emergency care.
How It Got In
Snakes enter through surprisingly small openings. Any crack or gap larger than a quarter inch is big enough. Common entry points include foundation cracks, gaps around pipes or wires where they pass through exterior walls, spaces under doors, and openings around basement windows. Homes with crawl spaces are particularly vulnerable, especially if the space isn’t fully enclosed.
In many cases, the snake used the same hole a mouse did. Rodents create and maintain pathways through foundations and walls, and snakes simply follow the scent trail right through.
Sealing Your Home Against Snakes
Prevention comes down to closing gaps and removing what attracts snakes in the first place. Start with a careful inspection of your foundation, working your way around the entire perimeter of your home.
- Foundation cracks: Seal cracks in concrete, block, or brick foundations with mortar. For gaps around pipes and wires entering the house, use latex caulk or expanding foam. Close all openings larger than a quarter inch.
- Under structures: If snakes can crawl under your home, porch, shed, or deck, block access with packed soil, bricks, sheet metal, or hardware cloth. The barrier should extend about 6 inches below the soil surface, since snakes can push through loose soil but can’t dig through compacted ground.
- Wooden structures: Repair holes in wood siding or outbuildings with sheet metal or fine-mesh hardware cloth.
- Drains: In rural homes, check that snakes can’t enter through septic or drain pipes.
Equally important is reducing what draws snakes to your property. Keep grass short around the foundation. Clear wood piles, rock piles, and ground-level clutter that provide cover. Most critically, control rodent populations. If mice can’t get in, snakes have little reason to follow.
Snake Repellents Don’t Work
Commercial snake repellents, whether based on chemicals, strong smells, or vibrations, have no solid scientific evidence supporting their effectiveness. Products using mothballs, sulfur, or pepper rely on the assumption that snakes are repelled by strong odors. But snakes detect chemical signals through their tongues and a specialized organ in the roof of their mouth. The scents humans find overpowering often mean nothing to a snake.
A snake looking for food, shelter, or warmth will move toward those things regardless of what you’ve sprinkled around your foundation. Repellents can actually make things worse by creating a false sense of security that leads you to skip the exclusion work that actually prevents entry. Your time and money are better spent on a tube of mortar and a bag of hardware cloth than on any repellent product.