In an Aesop fable, a thirsty crow wanting to drink from a pitcher must first raise the water level, so he drops pebbles in the container. In real life, the Eurasian jay can perform the same task. But just how smart is it?

Researchers challenged jays and human children with puzzles like the one in the fable. And until the kids reached the age of eight, their results were similar to the birds'. The study appeared in July in PLoS ONE.

In one test, a prize was put in a tube of either water or sawdust. About half the birds needed multiple trials to learn that dropping stones into the liquid, but not the dust, lifted the reward up to within reach.

When children between four and seven were faced with the same test, they learned in a similar fashion, taking about five trials to realize that the token in the water tube could be retrieved—although they did pick up the task faster than the birds. Older children learned more quickly, and those aged eight or older solved it the first time they tried.