You have to use a fine-toothed comb to ensure your cat has lice. They are the same as those used for humans, children, or adults. You'll pass the comb carefully through your cat's hair, preferably in the neck area. Then, while keeping the comb horizontal, you'll examine what you've got on the comb's teeth. Nits may be confused with skin flakes or dandruff. But if you see forms moving slowly along the teeth, it means you caught some lice: you need to consider treating your cat.