You should look up the lesbian lizards, not the official name of course. They are in New Mexico, apperently a mutation occurred in one female lizard that cause her to lay exact clones of herself, all the offspring inherited this mutation, so now the region is over ran with this female only lizard species, all clones of the original/each other.

To stimulate egg production they all get together and roll around in a pile.

Edit 1, link: https://en.m.wikipedia.org/wiki/New_Mexico_whiptail

Edit 2, the place, I was way off!