15 Terrifying Animals That Are Way Smaller Than You

When most people think of the terrors of the Amazon basin, there are a few notorious animals that come to mind immediately: the piranha, the anaconda, and the caiman being among the most notable. However, while these animals can (and do) attack humans, there is a far smaller threat to humans who might want to enjoy those waters: the candiru.

Normally a parasite that feeds on the blood of other fish, this animal is also attracted to urine and feces, and in the former case, will try and attach itself to the source. In other words, if drawn to the smell of urine, this animal will swim up a human’s urethra and bury its spines into the skin.

There has been at least one documented case where a man had a candiru insert itself into his urethra, and both the attack and subsequent removal process were excruciatingly painful.

Lesson learned: if you want to use the bathroom in the Amazon, don’t go in the water. You never know what’ll bite you in the ass…or genitals, in this case.