Sep 23, 2013 - 12:07 PM
The only way to really know if you have fleas in the car, house, cat, etc, is to physically see them.
Sometimes, you can take a white towel and place it on the floor. At night, a bright light like a desklamp, placed over the white towel can attract them.
If you see fleas on the towel, then you know you have them. If not, check the cat and see if you can find any on the cat.
Other than this, there are no easy ways to determine if you have fleas other than seeing them or getting bit.