my flatemates female cat humps her sister.

my flat mates have 2 FEMALE cats who are sisters. they aren't sterilized and recently i caught sabrina mounted on tabitha as if to mate her, and she was biting her neck. Sabrina's been on heat recently..is this normal behaviour for unsterilized cats? where do female cats learn this behaviour(the mounting part) when they haven't been in contact with any unsterilized males? they are over a year old, they seem to be doing it quite alot when they are on heat!

The mounting is also a dominance thing, and both are instinctive.

Are you going to be getting these 2 females spayed soon?

i'm not sure, its up to my flatmates whether they are going to do it or not. they keep putting it off saying they don't have any money soo..*shrugs*
its annoying though cuz when sabrinas on heat she caterwauls really early in the morning (and everyother time) and wakes me up! then she annoys my boy mickey who's sterilized and has none of it..hehehe

Well being in heat is not a pleasant experience for the cat either, it can be painful for them!

She can think of it this way, if she gets her spayed now, their is less chance she will have to pay for something else later down the line due to NOT being spayed, an even more expensive problem!

http://www.peteducation.com/category...cls=1&cat=1364

Yea, it's pretty normal behavior. My cats Niko and Mischeif used to do that before Niko was spayed. I believe it's just a part of instinct.