I've had cats all my life. I adopted a cat a few months ago. He was a stray, is believed to be around 4 years old, and was already neutered when brought into the cats protection. He's a lovely cat, and has settled in fine, but I only today noticed that he humps blankets. He likes to hold the blankets in his mouth, knead with his paws and purr. I thought this was quite cute, but then I noticed that he mounted the scrunched up blanket, and was humping it! I genuinely didn't know this was a thing with cats.