Animal Senses

 From:  http://www.cracked.com/article_19952_the-6-most-mind-blowing-animal-senses.html

Vampire bats are the only mammals that subsist entirely on blood -- otherwise, we'd just call them "bats." Getting their nightly blood dinner, however, requires a supersense that you probably didn't even know existed.

That nose that God forgot actually can sense the heat of your blood flowing through your veins.
Its nose-lip combo contains infrared heat cells that can sense the warmth of the blood at a distance. The crazy part is that they know where the best veins are.
Their system for heat detection is so efficient that they don't waste time. The vampire bat hones right in on the vein, first time, every time.

 "Gross, these pork chops are still raw!"

Catfish Are Giant Swimming Tongues

Yes, catfish are just huge, fish-shaped tongues, continuously licking our waterways.
The average person has about 10,000 taste buds, all in about the same place -- the mouth. According to one neurophysiologist who happens to be a catfish expert, a small 6-inch catfish can have over 250,000 taste receptors located all over its body. Or as he put it, it'd be like "if the tip of your tongue grew out and covered your body." Which is to say, you cannot touch a catfish somewhere where it cannot taste you.
Can you imagine walking through a room and tasting THE ROOM as you went by? That's what it's like to be a catfish ... all day and all night. Water pollution? Tasted it. The collective pees and poops of all the water animals in its vicinity? He tastes that shit in his sleep -- literally. There is nowhere for this animal to hide from the taste of the nastiness around him.
Of course, the catfish's sense of taste is how it locates and tracks down its food. Most of its taste buds are concentrated on its Fu Manchu mustache*, which kind of acts like a taste antenna as it swims through the current, tasting for the putrid slime trail of some prey it can swallow up

A Narwhal's Tusk Is a Huge Sensory Organ

 For years, scientists have wondered what the hell was up with narwhals, the bizarre creatures that look like manatees, only with gigantic horns growing from their skulls. Are they the unicorns of the sea, and if so, do you need a human virgin to trap them? These are the questions that even science can't answer.

What we have figured out is what's up with the narwhal's single tusk. For one thing, it's not a tusk -- it's a tooth. One long, weird, spiral tooth. But what we didn't know until recently was that the narwhal's tooth is covered with 10 million nerve endings. It's not a weapon or a hunting tool , as previously assumed. It's a sensory organ capable of things we're just now starting to figure out.

A Spookfish Can Hunt and Keep a Lookout Simultaneously, With Mirrorvision

If you had to guess which parts of that nightmare are its eyes , you'd go for those big orange spheres. But the reality is much cooler than that.
You see, fish that live in the endless night of the  depths face a problem: they have to look for food while staying alert against their own predators. You almost need eyes in the back of your head ... or the ability to look up and down at the same time. This fish does that, with internal mirrors.

The spookfish has split eyes, so it can see in both directions at once -- it's literally like having eyes in the back of its head. It's actually not a separate pair of eyes, but a complicated system that uses a curved mirror of reflective plates to collect the miniscule bits of light to be found a half-mile under the surface. So it's less like having eyes in the back of your head and more like having a pair of those sunglasses with mirrors that let you see behind you. It is the only vertebrate creature on earth that does this.
It makes a little more sense looking at it from the side:

The eyes are going the opposite direction you think -- the little black eyes on the bottom are looking up, for food. The big "eyes" on top are actually the backs of this mirrored surface, which collect little flashes of bioluminescence below that signal a predator is coming (the spookfish is vulnerable from below, something else useful to know if you ever have to fight a giant one).

Dolphins Use Holographic Imaging to See Inside You

  Everyone loves dolphins. They're playful, lovable and intelligent, and they rarely ever kill just for the fun of it. But when they do decide to murder you, they have some state-of-the-art equipment to help them.

You may know already that dolphins have sonar that is far superior to their vision, creating their adorable dolphin sounds and detecting how they bounce back. In fact, the sounds they hear create a kind of holographic image in their minds. As in, they perceive echoes as 3-D shapes and textures. Dolphins can "see" sound. And if that wasn't cool (or weird) enough, they can look right inside of you.
That is, their ultrasonic clicks penetrate flesh, giving them an X-ray view of your bones and innards. A talent that they've been known to employ when killing other creatures, because they will target vital organs when they attack.
How accurate is it? Well, tests for sensitivity show that they can distinguish between two objects that differed in width by the length of a human hair from 26 feet. Oh, and they can stun fish with concentrated bursts of sound, too. That's supervillain level, right there.