I think your situation is a bit different in that Basil is really a baby compared to your other kids. Babies need a little more attention I think. I was feeling bad about paying more attention to Calvin than Hobbes too. They are brothers and the same age. Calvin is a small slinky lovebug where Hobbes is a big and fluffy and very mellow. Never demanding attention and doing his own thing. Lately I've made sure that everytime I tell Calvin I love him or give him pets and attention (that he demands!) I do the same for Hobbes. It seems to have lessend his aggresion toward Calvin a bit.