5 Most Incredible Discoveries of the Week

A surprising animal sighting and the sinister sexcapades of female praying mantises have brought us into 2015 with a bang:

• Binge Drinking Does a Number on Your Immune System: The New Year's Eve damage is done, but for future reference: Binge drinking could hurt your immune system. Researchers gave vodka shots to subjects and found that two and five hours after "peak intoxication," the immune system slowed, with a reduction in two types of white blood cells key to immunity.
• Hungry, Desperate Female Mantises Do Hungry, Desperate Things: Specifically, they engage in sexual cannibalism, which involves luring a male for sex only to eat him. But new research suggests they also deceive by pheromones, as the hungriest females in the poorest health send out scent signals to males that they are in fact healthy and primed for copulation. Poorly fed females "attracted significantly more males"—and that's not the end of the bad news for the guys.

• First Bobcat in 100 Years Spotted on Ga. Island: Remote-sensing cameras have captured images of a lone bobcat on Jekyll Island, the first of its kind confirmed on the island since a photo from the early 1900s showing pelts hanging in the gamekeeper's cabin. It's possible the elusive animals could have been hiding out for many years—but scientists have alternate explanations for the bobcat in the picture.
• Ancient Ships Found Alongside Human Heads: The remains of 37 Byzantine shipwrecks are giving archaeologists a first look at that empire's long, oared galleys—and may reveal how shipbuilding evolved during the Middle Ages. The site also yielded human skulls, and researchers think they know whose heads they are.
• Exploring Ants Turn to the Left: Researchers are finding that ants carry an innate directional bias, in their case almost always turning left when exploring new territory. Why? One researcher explains why it could be both an efficient and safe means of navigation.

Click to read about more discoveries, including the world's second-biggest insect. (More discoveries stories.)