Hi, was wondering if there is any advance warning when a cat is going to go into heat? Tia is just five months and still to my eyes anyway very small. I am planning to have her spayed but would like to wait until she is a little bit bigger. I have always had either Toms(neutered) or previously neutered females so I am a bit in the dark on what to watch for if there are any "early warning" signs. I know that they roll and call, other than that I am in the dark....info please? Thanks alot.