Cuckoos lay their eggs in the nests of superb fairy-wrens, leaving all the hard work of raising the chicks to the wrens. But superb fairy-wrens have a remarkable strategy for recognizing their own chicks. They teach their young a secret password that helps distinguish them from cuckoo chicks. A new study shows when fairy-wrens detect the presence of cuckoos nearby, they up their teaching efforts.Read the whole story at Zoologic:  To Beat a Parasite, Birds Teach Their Young a Secret Password.