butterflys

Butterflies eat poop and drink tears.

Butterflies don't just drink nectar from flowers. Many of them consume a whole host of revolting things, from poop to urine to decaying animal flesh. They'll even drink the tears of reptiles to get some much-needed sodium.

Scientists can use these less savory preferences to attract and study butterflies: Researchers trying to attract tropical skippers will spit on a piece of tissue and put it on the ground, a method known as the Ahrenholz technique [PDF]. Butterflies are attracted to the saliva-soaked tissue because it looks like bird poop, and they stick around because it provides them with sodium and other nutrients. Meanwhile, their presence allows scientists to photograph and collect them.