Biscotte and Wellington continue their games and both enjoy a good wrestle (usually on my bed around 6.30 AM). But I have noticed the last couple of days that at some point during the 'fight' Wellington gets hold of Biscotte by the scruff and then starts to straddle her. She just crouches down and stays still. He then gets a strange look on his face as if to say 'What is happening? Why am I doing this?' and lets go. She has not shown any other behaviour but I wonder if she is coming into heat and he senses it. I can't get her spayed for another two weeks (one month after her vaccinations) but she is six months old now so it could happen any time. She is so small compared to Wellington that I still think of her as a kitten.