Why don’t birds fall out of trees while sleeping? Science has the answer

Have you ever seen a bird sleeping on a thin tree branch and wondered why it does not fall? While humans may lose their grip when their muscles relax during sleep, many birds can remain safely perched for hours. The answer lies in the structure of their legs, feet and tendons. But the explanation is not exactly the same for every bird.How birds hold on to branches while sleepingMost small birds that regularly sit on branches belong to a group known as perching birds (passerine). These birds have feet adapted for gripping branches, with three toes pointing forward and one toe pointing backwards. The backward-facing toe is called the hallux. Together, the toes help the bird hold a branch from different sides. When a perching bird lands on a branch, its legs bend at the knee and ankle.