Fish recognize faces
Damselfish can recognize members of their own species by their unique facial patterns, detectable to us only under ultraviolet light. The fish were tested under conditions where they were rewarded for swimming toward an image of a fish-face they had seen before over a novel image. They overwhelmingly picked familiar faces. Since fish swim in groups, it may benefit them to know their neighbors.
Also, the title of the article should be "Not just a human skill!" - as it is surprisingly not a human skill...
Baby spiders more bold with parents
The social spider Stegodyphus dumicola hang out in groups of hundreds - and show some signs of cooperative raising of offspring. Turns out that being around adults helps juveniles feel more comfortable when hunting. When placed in groups of just juvies, the spiders were more hesitant to attack a cricket (their prey) than when with adults. Read more!
Sibling rivalry: shark eats siblings in the womb
Sand tiger shark moms start off with up to 10 embryos in the womb, but by the time it's time for birth, only two at most remain. Why? Those embryos are apparently snacking on each other during her pregnancy.