Hi,
I have had my 2 year old cat for about 6 months, he was neutered about 3 months ago.
He had got into a nice routine, going out at night and coming home in the morning to spend all day in the house asleep. I would try to have a little play with him after his breakfast, but he was always keen to get on his chair and start snoozing. However, over the last couple of weeks his behaviour has really changed. He comes in in the morning, eats and then goes mad running around, hiding, pouncing and worst of all he has a new habit of jumping and biting my (usually) bare legs. I think he's only playing, but still. When he does this I raise my voice, but he still keeps doing it... I usually have to send him outside again for an hour to run around and calm down...
For the rest of the day he is very calm, likes to be cuddled etc.

Has anyone any idea why his behaviour might have changed so much? And how I can stop the leg biting?

Any help much appreciated!
Thanks.