We occasionally get asked about how to discourage venomous snakes from living in a yard. Unfortunately, people do run into unwanted snake friends in their yards that could possibly pose a health risk to them, their kids, and/or pets. If you live near suitable habitat for a venomous snake species, encounters with them are going to occur. The following are some suggestions that may help discourage the snakes from using your yard. Remember it’s always safer for you and the snake if you don’t try to kill it. The snake will react negatively at an attempt to kill it (understandably) and it could potentially injury you. We want to see both human and snake survive any encounters.
The best way to discourage venomous snakes from using your yard is to remove any suitable habitat and food sources. Remove all rock piles, cover boards, wood piles, and other such places a snake could hide. Of course, BE CAREFUL when removing anything from your yard in case there is a snake under it. Also, trim and/or remove heavy brush, tall grass, rotten stumps, rodent burrows (make sure they are not tortoise burrows), etc. Always keep your lawn mowed short. If you are worried about cottonmouths consider not installing a water feature like a koi pond that would look very inviting to a semi-aquatic snake.
Make sure you keep rodents under control too. Rodents are major food sources for a lot of venomous snakes and will attract them to your property. If you experience any problems with mice, rats, squirrels, etc. take care of it immediately but naturally. Avoid using poisons to kill any rodents using your yard. A poisoned rodent can be an easy prey to an unsuspecting snake or raptor or other such predators. When the snake or other predator eats the poisoned prey the toxin can be passed on to the snake either making it ill or potentially killing it. Also, keep all pet food indoors. Pet food attracts rodents.
Check under and around your house. Porches, crawl spaces, steps, etc. are all ideal places for snakes to live. Fill in or tightly seal up any gaps in your foundation that a snake and mouse can fit through.
As for snake proof fencing, there are several options to use. You can build your own or have one professionally installed. If you don’t want or can’t afford to fence your whole yard you can fence the section of it you use the most, say your backyard. If you chose to build a fence yourself make sure you use a heavy mesh with no more than 1/4″ opening or a slick material that a snake cannot climb. The fencing should be at least 36″ wide. Bury the lower edge at least 6″ in the ground. The fence needs to be slanted outwards from the base at a 30-degree angle. All supporting stakes need to on the inside of the fence. Make sure there is no tall vegetation around or overhanging the fence.
No chemical repellents have been proven 100% successful at keeping snakes out of an area. As for the lava rocks, I can find no confirmation that they work either nor laying down rope.
Another idea is to have a local snake removal service perform a home inspection to determine what needs to be done on your property to discourage snakes. And if you’re worried about your dog then there are services designed to train a dog to avoid encounters with venomous snakes (though I don’t know how well these works).
The Snake Anti-Defamation League also suggests keeping the area around bird feeders clean because the scattered seed can attract rodents, which in turn attracts snakes.
Hope these tips help. Best of luck and be safe. Don’t forget that your local fish and wildlife service is a great resource too as is your local herpetological society.