Snakes. Why did it have to be snakes and spiders?

Guam, a tiny U.S. island in the South Pacific, is known for one thing and one thing only: a really nice golf course. Also: snakes. Ever since the brown tree snake was accidentally introduced to Guam in the 1940s, the species took off, having no natural predators and 12 native species of birds to eat.

Well, now Guam is down to two — count ’em: two — species of birds and plenty of snakes to go around. Oh, and did we mention spiders? Because, without birds to eat them, the spider population has exploded to 40 times more than that of other nearby islands. Scientists can’t even walk around the jungle without a stick to cut through the webs — they’re that thick, sometimes with dense swaths filling the gaps between trees.

So, the next time you see someone feeding the birds, shake their hand. That homeless person is on the front line, protecting us from a world of spiders, snakes and crawling skin.