Flamingos must hold their heads completely upside down to eat.

Flamingos have a special beak structure called lamellae. These are tiny, hair-like plates that act like a sieve or a filter. This system is similar to how some large whales use baleen to catch food. The flamingo uses its large tongue like a pump to move water in and out of its beak.The tongue can move back and forth up to four times every second. This creates a vacuum that pulls in water filled with algae and brine shrimp. The lamellae trap the food while the bird pushes out the mud and salt water. This process is very efficient for living in salty lakes.A flamingo's beak is shaped differently than most birds. Their top bill is movable while the bottom bill stays still. This is the opposite of how a human jaw or most other bird beaks work. This shape allows the filter to work perfectly when the head is submerged and upside down.The food they eat contains natural chemicals called carotenoids. These pigments are what turn a flamingo's feathers pink. Without eating enough shrimp and algae, their feathers would stay white or grey. Brighter pink feathers usually mean the bird is healthy and well-fed.