Northern paper wasps separated from group living may experience difficulty recognizing the faces of other wasps in their community, a study in Biology Letters suggests. Researchers observed the wasps after they emerged from their cocoons, isolating some and allowing others to socialize, then they examined the wasps brains, finding differences between the social wasps and the solitary ones.

Researchers have 3D-printed models of the shells of ancient ammonites and nautiluses to learn more about how the marine creatures evolved, saying the ammonites' complex internal patterns, called sutures, may have helped them be more buoyant. "The 3-D printed models allow the fabrication of incredibly intricate chamber walls that have details comparable to the living animals," said David Peterman, author of a study on the process published in Scientific Reports.

People who lived in what is now Spain and France between 14,000 and 40,000 years ago may have purposefully sought out caves with low oxygen levels so they could have a hallucinatory experience while creating cave art, according to findings reported in Time and Mind. Computer simulations suggest the depleted oxygen in caves where paintings have been discovered could have resulted in hypoxia, which can cause hallucinations.

A new area of the Milky Way bursting with huge blue stars has been detected by astrophysicists putting together a comprehensive map of the galaxy, and they describe the find in Monthly Notices of the Royal Astronomical Society. The region was found between the Perseus constellation and the Orion Arm and researchers say the stars, which are extremely hot, are close to blowing up.

Stress caused by predators may cause Trinidad's killifish to grow more brain cells than those who aren't preyed upon, a study published in the Royal Society Proceedings B suggests. Most fish families have less brain cell production when faced with predators, unlike the killifish, says researcher Kent Dunlap.