Do you want to treat the pet? I suggest frontline, advantage, or a veterinary reccommended treatment if fleas/ticks are the problem. They are expensive but work quite well. We won’t even do a flea treatment unless the pets are on one of these.
Otherwise, are you wanting to treat your house for fleas or a different insect? As much info as you can provide concerning the insect problem, your geographic location, number and nature of pets, etc. will help.