My male cat has started crawling on his stomach and sticking his butt up in the air. He is about 10 months old and has not been neutered. He is an indoor cat and has not exhibited this behavior before. He is also walking about meowing where previously he has been a quiet cat.

Please get him neutered IMMEDIATELY! Soon he will be marking his territory (your house) by spraying a very strong-smelling urine on carpeting, furniture, beds.

Neutering him will keep him from impregnating any unspayed female cats he comes in contact with and causing even more unwanted kittens to be born into this world. He will be healthier, will live longer (15 years vs. half of that or less), and will prefer staying indoors where he is safe.

On second thought, are you sure he is a male?

Yes he is male. I have 2 neutered 16 year old cats. He will be heading to the vet in the morning.