Rattlesnakes are a group of venomous snakes native to the Americas known for their loud rattling tail. The tip of their tail, known as the rattle (middle), vibrates to deter predators or serves as a warning to passers-by.

The rattle is composed of a series of hollow, interlocked segments made of keratin, which are created by modifying the scales that cover the tip of the tail. The contraction of special "shaker" muscles in the tail causes these segments to vibrate against one another, making the rattling noise (which is amplified because the segments are hollow) in a behavior known as tail vibration. The muscles that cause the rattle to shake are some of the fastest known, firing 50 times per second on average, sustained for up to three hour ...

This glowing worm is the larvae of a species of click beetles, which belong to the family Eliteredae. Click beetles typically make a clicking motion to quickly escape predators. Of the 10,000 beetles identified, only 200 are bioluminescent. It is hypothesized that the beetle larvae glow green to lure prey such as ants and stick insets. When presented with these insects, the worms readily devoured them. While most beetles dine on flowers and other plant-matter, their larvae are mostly predatory. The insects wait with jaws open, and as soon as an ant or a termite flies in, their jaws clamp shut.


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