Caltech researchers studying the nervous control of nematode mating behavior have produced video footage of a male worm preparing to mate with a hermaphrodite. Allyson Whittaker, a senior research fellow in biology, and Paul Sternberg, the Thomas Hunt Morgan Professor of Biology, investigated the role of the excitatory neurotransmitter acetylcholine in regulating tail muscles to achieve an exploratory embrace. The video shows an intimate moment between two nematodes of the species Caenorhabditis elegans.

Bacteria are mostly known for making you sick—causing deadly diseases such as pneumonia, syphilis, cholera, tuberculosis, and meningitis. But not all microbes are malicious. In fact, your bowels bustle with about a hundred trillion bacteria—that's 10 times more microorganisms than you have cells in your body. In a recent article in Engineering & Science magazine, author Marcus Woo explains that these bugs aren't just harmless; they may be crucial for your health. Click here to learn more.