Rattlesnakes

November 18, 2021

Question: I followed the news story about the Santa Rosa resident who found dozens of rattlesnakes under his home. Should I be worried about rattlesnakes under my house? Are rattlesnakes aggressive?

Answer: It’s perfectly natural, and perhaps even an innate human reaction, to feel worried when hearing a story about a California resident finding so many potentially dangerous snakes so close. In general, rattlesnakes are not aggressive. They avoid conflict to the best of their ability because they don’t want to risk injury or death in a battle or to waste venom by biting something that isn’t prey. The most familiar way rattlesnakes avoid conflict is signaling their presence by rattling and taking a defensive coiled posture when a potential threat gets too close for comfort. If left alone, they will move away from the threat, not toward it. A lot of bites occur when people are trying to kill or move rattlesnakes. However, not all bites involve envenomation. They will sometimes “dry bite” as a warning. Rattlesnakes are distributed broadly across the state but are typically found in open habitats like grasslands, savanna and desert, often in and around rock outcrops when available. When they are found in homes and yards, it’s usually along a wildland-urban interface. However, coming across a den under a house like the one in Santa Rosa is incredibly rare. It’s important to recognize that rattlesnakes don’t seek out or prefer to live near people, but they will den under a home if there is an abundance of prey and if it’s the best available habitat in an area. The Santa Rosa story is a good reminder that we should be mindful of our surroundings when we spend time outdoors and around our homes, especially during warmer weather. Residents can make their yards rattlesnake safe by removing objects that attract them and their prey. This can include keeping vegetation away from fences, removing piles of boards or rocks around the home and repairing any holes in vents or other potential access points. For more information on rattlesnakes in California, please visit wildlife.ca.gov/Keep-Me-Wild/Rattlesnakes.