When we think about sleeping, it means lying down on a flat surface. After all, that's how our body rests.
However, there are animals and birds that have unusual sleeping habits.
Koala bear: These animals sleep for around 20 hours a day by hanging on trees. Staying up in a tree keeps them safe from predators like dingoes.
Shark: Sharks take a break by halting their speed and letting the body rest syncing with the flow of current. They, however, do not enjoy deep sleep.
Parrotfish: This colourful fish sleeps inside a clear cocoon made of mucous every night to safeguard itself from predators like sharks and eels.
Horse: Horses can lock their legs and sleep standing upright for short periods of time. They, however, lower themselves and tuck their legs to the front when sleeping for longer hours.
Bat: Bats like to hang upside down when sleeping. They also prefer to sleep in a group as self- protection. Their feet have special tendons that doesn't allow them to fall.
Sloth: Sloths love to sleep! They either balance themselves on forked branches of trees or hang upside down. Their long claws help when they remain suspended.
Flamingo: Flamingos are known to stand on one leg. They also sleep on one leg! In fact, they are never fully asleep as half of their brains are always alert and aware of its surroundings.