According to a new study, they whistle. Researchers slid a small camera through horses' noses to film what happened inside while they whinnied and made another common horse sound, the softer, subtler ...

A few small rodents like rats and mice whistle like this, but horses are the first known large mammal to have a knack for it.

Horses use their larynx to make two sounds simultaneously, so they are effectively singing and whistling at the same time ...

Cold weather drives rodents to seek warmth in engine bays, where they chew wiring and build nests from leaves, sticks and insulation.