Glow & Light Tricks

The Anglerfish fishes with a glowing lure that grows right out of its own forehead.

Why it works: The glowing "fishing rod" on the anglerfish's head is really a stretched-out fin spine, and the bright bulb on its tip is packed with billions of tiny living bacteria. The fish can't make light on its own, so it grows these bacteria inside the bulb and feeds them; in return, a chemical reaction inside the bacteria combines with oxygen to give off a blue-green glow. A young anglerfish actually takes the bacteria in from the seawater around it. Its very stretchy stomach and loose jaw let it swallow prey bigger than itself, and the strange mate-fusing trick works because anglerfish lost part of the immune defense that would normally reject another fish's body.

The Cuttlefish hypnotizes its prey by pulsing moving bands of color across its skin, freezing the target in place.

Why it works: The cuttlefish's skin is packed with tiny color sacs called chromatophores, and each one is ringed by little muscles its nerves can yank open or snap shut. Because muscles and nerves do the work (not slow chemicals), the color flips almost instantly, and mirror-like cells underneath bounce light to add blues, greens, and silver. When it hunts, it rolls dark stripes across its body; scientists think this swirling motion overloads the prey's eyes so the crab or fish can't tell the cuttlefish is creeping closer. And even though it is colorblind, it seems to match its background by reading how light or dark each spot is rather than the actual color.

The Platypus hunts with its eyes, ears, and nose shut, using 40,000 sensors in its bill to feel the electric pulses of its prey.

Why it works: When a shrimp or insect larva twitches its muscles underwater, those muscles make a tiny burst of electricity. The platypus closes its eyes, ears, and nose underwater, so instead it 'reads' those faint electric sparks with about 40,000 special sensors in its rubbery bill. Other sensors in the bill feel the ripples the prey makes in the water. Because electricity zips through water faster than ripples do, the electric signal arrives a split second sooner, and the platypus uses that tiny time gap to work out how far away its dinner is.