Watch a caterpillar turn into a butterfly, in 3D

What happens inside a caterpillar's cocoon? Scientists got to watch the whole process with the help of X-ray 3D scanning technology. In the video above, you can watch a caterpillar turn into a butterfly. Over the course of 16 days its breathing tubes (shown in blue) and its digestive system (shown in red) change shape and position within the body, while other structures grow from scratch.

Ed Yong has a great story to go with this, too. All about why it's important to actually watch the process happening in a single caterpillar, instead of just relying on the data scientists have collected from years of dissecting different caterpillars at different stages in the transformation.

The Butterflies of India: An interview with Isaac Kehimkar

Isaac Kehimkar is an avid naturalist and the author of The Book of Indian Butterflies Isaac's photostream of Indian Butterflies is at Flickr.

Avi Solomon: What early influences drew you to the study of nature?

Isaac Kehimkar: I grew up in Deonar, a suburb of Mumbai. It was a time when black and white television had just started in India with only one channel and no video games in sight. But Nature offered so many options. Deonar was still green and water in the streams was sparkling clean. The Monsoons were my season and catching fish and crabs with local Koli and Agri boys in the rice fields was my favorite pastime. That's the time I even dared (rather foolishly) to catch snakes too! With the rains gone and rice harvested, cricket pitches were soon paved in the rice fields and we played cricket till the rains came again.

Read the rest

"My Favorite Museum Exhibit": Butterflies eating a piranha

"My Favorite Museum Exhibit" is a series of posts aimed at giving BoingBoing readers a chance to show off their favorite exhibits and specimens, preferably from museums that might go overlooked in the tourism pantheon. I'll be featuring posts in this series all week. Want to see them all? Check out the archive post. I'll update the full list there every morning.

You've seen a lot of good taxidermy this week, but nothing quite like this. Renee Mertz sent me this photo of a diorama at Vienna's Naturhistorisches Museum, which depicts a group of butterflies greedily feeding off the carcass of a dead piranha.

This is not a spot of whimsy, people. This kind of thing really does happen. In fact, you can watch a real-life example (with a less-threatening fish substituted in for the piranha) in a video taken in Alabama's Bankhead National Forest.

The good news: The butterflies are not really carnivorous, per se. The bad news: What they're actually doing is still pretty damn creepy.

It's called "puddling" or "mud-puddling". The basic idea works like this: Butterflies get most of their diet in the form of nectar. They're pollinators. But nectar doesn't have all the nutrients and minerals butterflies need to survive, so they have to dip their probosces into some other food sources, as well. Depending on the species of butterfly, those other sources can include: Mineral-rich water in a shallow mud puddle, animal poop, and (yes) carrion.

When butterflies puddle over a dead fish, though, they aren't biting off chunks. Instead, they're essentially licking the dead fish—going after salt and minerals that seep out of the dead animal as it decomposes. Bonus: Some butterflies also like to lick the sweat off of humans. And a few species of moth have been documented sucking blood and tears for living animals, including humans.