Take a deep breath and don’t panic… There are times when it can be a single invader which could be why you aren’t seeing scratching or other flea related behavior… My foster was riddled with lice when he came home and trust me they scratch just like a dog or a cat….
I would still treat for fleas as eggs might be laid before you can end the nasty little insect… Revolution Puppy and Kitten is the best and safest I have found, under no circumstances should you use frontline or comfortis… There is a product that is made by advantage that is a combo for kittens, small cats, ferrets and bunnies if you are unable to get revolution puppy and kitten (in the pack with the pink/lavender marking)
Unfortunately in the US it can only be purchased with a prescription in some states so it depends on what your laws are for the product. This should not be a major problem as your vet should be able to provide it if a prescription is required. If no prescritpion required you should be able to purchase it at Walmart, Pet Stores and over the counter at your vets.
Quick recap Revolution is good, Advantage is ok, frontline and comfortis is bad.