Hawaiian Happy Face Spider "Hanai Keiki in the Family"

The Hawaiian Happy Face Spider (Theridion grallator) is a silently tropical leaf resider. If you are hiking through the wet forests of Hawaii, the colors are difficult to see as it blends in with the foliage, but one thing sticks out, its happy face. It gets its famous nickname because many of them look like they have a bright, joyful emoji painted right on their backs, complete with a big grin and squinty eyes, and a yellow body that seems friendly in its neon lit shimmer. But don't let the smile fool you; this teeny-tiny carnivores are still small huners, a dedicated mother, and a completely endemic in the valleys of Hawaii—and finding one is harder than you might think.

This spider will live its entire life upside down under a slippery green leaf, hiding from hungry birds, while spinning a web so thin it looks invisible... A small leaf is huge to the Happy face Spider, since it measures only about one-quarter of an inch (5 millimeters) long, with long, glassy, translucent yellow legs that has really small hairs. They are so see-through that if they eat a dark bug, you can actually watch their abdomen change color right through their skin! They thrive in the high-humidity, high-elevation wet and mesic forests, specifically on the islands of Oahu, Molokai, Maui, and Hawaii Island.

What makes them hard to find is not just that they are small, but they only like to come out at night time. During the day, they press themselves completely flat against the underside of a leaf, staying perfectly still so the filtering green-yellow light makes them invisible to predators. But once the sun goes down, they wake up to hunt, they eat all sorts of small insects like mosquitos, fruit flies, and other sorts of flies, which make up about 70% of their diet. The can be found more often than not on specific plants like the Kanakao or Clermontia for their big, broad leaves that offer excellent shelter from the rain and plenty of moisture. 

Their lifespan averages around one year, during which they will molt several times, gradually getting larger while maintaining their translucent, fragile look. Still they remain very small... even when they reach their mother-phase, but what's interesting is that they are a spider that sticks with their cluster of eggs and wraps them in a silken sac, because most spiders lay eggs in a sac and run for the hills. When the babies (spiderlings) are ready to emerge, the Happy face spider mother actively helps them by loosening the silk of the sac. She will catch flies, chew them up, and feed her babies through a process of regurgitation. 

The spiderlings live together on their mother's leaf for up to two months, sharing meals as a big family, even inviting other spiderlings to the lead if they are abandoned... dinner is set up and ready until they are all mature enough to move to their own leaf in the leaf real estate market.

Even though they are spiders, they cause zero anxiety for humans because they don’t bite us, they aren't venomous to people, and they are just nice to look at.