These highly impressive spiders are brilliantly colored, very big (two to three inches across), and like to hang right at face-height in nearly invisible webs strung between branches. They are also known as banana spiders, although they do not like to hang out in bunches of fruit — they just are the color (and, it feels like, the size) of bananas; other common names include golden orb-weaver and giant wood spider.
Male spiders are much smaller than the big, beautiful females, sometimes 10x smaller. Female spiders build an egg sac which holds up to 3,000 eggs; when the spiderlings hatch, they form a large communal web until they are large enough to disperse and start a solitary web of their own.
Nephila live permanently in their webs, which can be as large as five feet across, with a main web and then several extra layers of web on either side. These extra layers often contain debris; they may be acting as “deflector shields” to protect either spider or web, or they may simply be the remains of previous webs. The web has a distinctive golden sheen to it (due to carotenoids in the silk) — the color may help attract bees to the silk, or may act as camouflage in shadier areas. Humans have occasionally tried to make things out of the silk; things like garments (capes and the like) have proven possible but impractical. There is some interest in using the substance as a scaffold for tissue engineering.
These spiders change their position in their webs to help regulate their temperatures. In full sun or hot weather, they will move so that their abdomen shades the cephalothorax from the sun. In cooler weather, they position themselves so their whole body catches the sun.
These large spiders usually eat flies, beetles, and flying insects, but can catch prey as big as small birds and bats. When prey is plentiful, they will cache the extras in silk wrappings above the hub of the web. Nephila spiders are large and appear dangerous, but the effects of their venom are negligible on humans and they are generally harmless (although their large jaws will give you a nasty pinch if provoked).