How do you find where fleas are hiding?

I am lucky not to have a huge flea problem with my dog and my daughter's dog. The first thing we do is keep them bathed with Dawn dish soap. It seems to kill fleas on contact. I have used the dish of soapy water and the lamp at night. It works well to attract the little monsters and drown them. I know they like to hide in crevaces, so vacumning around the edges of the room and between the cushions on couches and chairs helps a lot. I have sprinkled my yard with bug killer and that made a difference too. It is just an ongoing battle and it is year around in the south.