i had a similar problem with rabbits. i could never tell boys from girls. i had a favorite rabbit named bert (our guinnea pig was ernie) in my classroom for 3 yr olds. bert would let the kids pick him up and carry im any old way, and would sit in their lap, and was always very sweet. my co-teacher had a white rabbit, a boy,too, and she wanted the 2 to meet.a bad idea! if bert and twinkie were both boys they would fight to the death. if bert was a girl she'd be pregnant in seconds-really!. the inevitable happened! she put them together. bert had 5 babies.