Potentially deadly insects known as “kissing bugs” have invaded the entire southern half of the United States–including California.

The bugs, officially called triatomines, have been found in more than 25 southern states, according to KTLA 5. California has seen reports of at least four of the 11 species of the insect in the state.

Triatomines are called “kissing bugs” because they are known to bite humans on the lips. According to the Centers for Disease Control and Prevention (CDC), the bites can be deadly if the bugs are infected with parasites and defecate in the wound. That can cause Chagas disease, which can be fatal if untreated.

The bugs are nocturnal and can be found in a variety of places both indoors and out, including in cracks and holes of houses, under or around mattresses, underneath porches and in animal nests.

If Californians or anyone else should stumble across the bug, the CDC recommends not stepping on them; instead, one should trap the bug in a container and fill it with rubbing alcohol, or, in the absence of alcohol, freeze the bug and take it to a local extension service or university health department.

To keep the bugs out, the CDC recommends: