I desperately need help! I used to love this book series as a kid but I can't remember the name of it or who wrote them. It was this family of lime green alien like creatures with two children, a boy named Rex and I think the other one was a girl. I'm not actually sure if they were aliens, they could have been some kind of bugs. But they had human qualities. I remember in one book the kids wanted a pet and went to the pet store to pick one out. That's all I remember. If anyone knows this series, please help me! Thanks!