If you look around your house you will find their entrance, through the
ground, or wall, problem is when to spray the nest you will have 1000s
in your basement mad as hell. I dont know your basement construction, or
how many people or pets, but you will have to spray the basement, at the
same time. I used a gopher bomb in the basement and hit the nest with
ortho sevin , then left for a day, you can do it yourself, but you
should get a price and means of attack from a pro, as the summer goes
on their numbers wil grow.