In the same way that humans can be either left- or right-handed, crows — who are known for being especially good at wielding sticks as tools, especially to pull larvae out of burrows — favor either the left or right side of their beaks. But this may not have anything to do with the beak itself: Instead, a crow's beak "handedness" may have to do with its eyesight.

According to research published in Current Biology, these birds are compensating for the fact that one of their eyes is better than the other.

"If you were holding a brush in your mouth and one of your eyes [was] better than the other at brush length, you would hold the brush so that its tip fell in view of the better eye," study author Alejandro Kacelnik of the University of Oxford said. "This is what the crows do."

The researchers performed tests to determine the eye dominance of nine crows and found that their dominant eye could reliably predict their preferred beak side — if their left eye was stronger, they held the tool on the right side of their beak, which put the tip of it in front of the left side (and vice versa).

Humans don't have this same correlation: Only two thirds of us are right-eye dominant, but 90 percent of us are righthanded.

Don't mess with electric eel

Turns out electric eels are neural puppetmasters, using electricity as the strings to manipulate their prey. While the serpentine creatures regularly use their zapping powers to temporarily paralyze unlucky fish, they can also send out a shock that will cause hidden fish to twitch, betraying their positions and making them easy targets.

The findings, described in the journal Science, reveal a hidden power lurking inside an already shocking animal. "It looks like the eel's been out there reading the literature," said study author Kenneth Catania, a neurobiologist at Vanderbilt University in Nashville. "It's been studying up on motor neuron physiology."

Using electricity, the eels were able to make their prey move on command, and also make it freeze. And all of this happens within a tiny fraction of a second, Catania said. "I was completely amazed," he said.

Porpoise on verge of extinction

Little is known about the shy vaquita porpoises that spend long periods feeding under muddy coastal waters off Mexico, but this much is certain: They are the world's smallest porpoise and they could soon disappear forever if they keep turning up dead in fishing nets.

The latest stock assessment by a panel of international scientists showed that there are fewer than 100 left and that they are declining at a rate of nearly 20 percent a year. If vaquitas vanish, they would be the first known cetacea in North America to do so, and the first in the world since the Chinese river dolphin was declared extinct in 2006.

News services