The bombardier beetle spits out a dangerous jet of venom to ward off predators, and scientists are now figuring out how it expels the toxic stuff.

According to an article in April's issue of Physics World, the beetle's abdomen essentially harbors a small chemical lab and combustion chamber. The gases react inside the confined chamber, eventually cranking up the heat and pressure to a point at which a valve is forced upon, and the toxic jet spurts out.

German scientists have demonstrated that the tattoo needle may be a more effective way of delivering vaccines than the standard injections. In tests on mice, the tattoo technique proved more successful in stimulating an immune response—tattooing a vaccine produced 16 times more antibodies in the mice.