As if that weren't scary enough, crocodilians have incredibly powerful senses to detect their prey. Their eyesight above water is top notch, and thanks to vertical pupils that can open up extra wide to let in additional light, they also have keen night vision. And even though you can't see their ears, don't be fooled -- these small slits are sensitive enough to hear offspring calling from inside their eggs [source: San Diego Zoo]. Even their sense of smell is highly developed due to special organs in their snouts.