A healthy and energetic mule named Idaho Gem is the first member of the horse family to be cloned, joining the barnyard of cloned animals that now includes sheep, cows, pigs, cats and rodents.

You’re likely familiar with the idea of the sterile mule: a hybrid animal born of a horse and a donkey that is unable to breed. But what about a fertile mule whose teeth just aren’t right for chewing ...

Horse plus donkey — it seems like an unlikely combination. I mean, they're different species! And yet, when they get together, they can produce a mule or the lesser-known hinny. Either way, those ...

If mules were Freudians they would be kicking mad. They always have parents, rarely have offspring. Because they are the hybrid, infertile offspring of a mare and a jackass, race suicide is as ...