Within a few more generations, Belyaev had enthusiastically tame foxes that rushed over to lick their human friends. What was most surprising, though, was that the foxes had also changed in appearance. They had curly tails, floppy ears, slightly more feminine heads and white patches on their foreheads – as are often found in domesticated cattle, horses and other pets. They also had larger litters and began breeding at younger ages and out of season. Belyaev repeated the experiment with mink and rats, with similar results.
