There's a reason why Spider-Man makes for a better superhero than, say, Golden Retriever Man. Nothing against our canine friends, but spiders have the upper hand, or rather leg, when it comes to awesome biological functions and tricks. After all, it's not really a superpower to roll over and play dead.
But you know what is? Producing giant webs of shockingly strong silk to trap enemies. And that's exactly what Darwin's bark spider (Caerostris darwini) does. This species of spider weaves enormous webs that span across bodies of water, with anchor strands up to 82 feet (25 meters) long [source: Agnarsson et al.]. Such an impressive web won't do any good, however, if it falls apart when a fruit fly sneezes on it.
So scientists decided to test the spider's silk strength, and they found that the strands were twice as tough as any other silk studied and 10 times stronger than Kevlar [source: Agnarsson et al.]. It can take incredible amounts of kinetic energy before breaking, so no measly insect can escape the spider's web.