Updated: Jan 16
Have you ever noticed your cat humping a soft blanket or perhaps a pillow? This behavior is normal - even for a neutered, spayed or female feline.
Experts believe that this behavior is an act of dominance or a way to ease stress. Older female cats may grab a kitten by the neck and appear to be humping him. This is more of a maternal discipline behavior rather than a sexual one; mother cats often grab their kittens and pin them down to put a stop to their bothersome behavior.
The best way to put a stop to this behavior is to catch it before it begins. If you see your cats body language show dilated pupils, purring, an arched back, and kneading very excitedly - distract them with a game of 'feather chase' or 'toss the mouse'. If you catch your cat in the act of humping, gently pick them up and set them down on the floor and give them a firm "no".
If you find that your cat humps compulsively, I'd suggest consulting with your veterinarian to make sure there are no infections. If your cat comes back infection free - I'd recommend giving them a sort of stress relief (an hour of play, using pheromone diffusers, or even doing some basic obedience training with them).