They can spend up to fifteen years alive inside their cocoons. When they decide the time is right, they can burst out of the pupa in the direction of the nearest source of warmth and vibrations, which will probably be a luckless mammal. Adult fleas try to spend as much time as they can attached to a hairy mammal of the right species. Different species of fleas are actually specific to different host species, to varying degrees of specialisation. Cat fleas which bite humans die.
Fleas have remarkable corkscrew genital apparatus.
They can remain coupled under the most trying circumstances, such as, caught on a flea comb and about to die. Your cat is a flea dating agency. All the flea has to do is keep biting, keep reproducing, and keep running and jumping to avoid getting squashed. Unfortunately, these are things at which fleas are very good. Some things to consider Temperature.