While biologists used to believe that showing a preference for the right or left side is unique to humans, more and more studies are showing that other animals, like kangaroos, do it too.

For the first time, scientists have discovered handedness in tarantulas.

In a recent study published in the Journal of Zoology, scientists put captive male Honduran curly hair tarantulas into a T-shaped maze with two possible choices at either end.

The team put the grapefruit-size arachnids through a variety of tests. In a set of odor-based experiments, the tarantulas could smell live cockroaches—a favorite prey—at the end of both tunnels; in another, the male tarantulas could detect the smell of female tarantulas. In both cases, the males chose the