Animals — Page 8

The axolotl loses its external gills when it becomes an adult.

The axolotl keeps its external gills throughout its life, a phenomenon called neoteny. Unlike other amphibians, it…

The sand temperature determines the sex of turtle hatchlings.

In many species of sea turtles, the sex of the hatchlings is determined by the temperature of the nest sand…

The three-banded armadillo rolls into a perfect ball to defend itself.

The three-banded armadillo (Tolypeutes tricinctus) is the only armadillo that rolls into a perfect ball, completely…

The nest temperature determines the sex of crocodiles.

As with turtles, the sex of crocodiles is determined by the nest temperature. In crocodiles, lower temperatures…

Elephants communicate only through sounds audible to humans.

Elephants also communicate through infrasounds, low-frequency sounds below the limit of human hearing. These sounds…

The lamprey has no jaw.

The lamprey is a jawless fish that attaches to prey with a circular mouth full of keratinous teeth. It feeds by…

There is a parasite that replaces a fish's tongue.

Cymothoa exigua is a parasitic crustacean that attaches to a fish's tongue, sucks blood until the tongue atrophies…

Tardigrades can survive 30 years without water.

Tardigrades enter a state of cryptobiosis when they lose 99 percent of their body water. In this state, metabolism…

The mimic octopus can imitate more than 15 different animals.

The mimic octopus (Thaumoctopus mimicus) is capable of imitating the shape, colour and behaviour of more than 15…

The hydra has a life expectancy of about 20 years.

The hydra is a freshwater animal that appears to be biologically immortal. Its tissues are composed of stem cells…

There are worms that eat whale bones.

Worms of the genus Osedax bore into the bones of dead whales and feed on the bone marrow and collagen. They have no…

The woodpecker's tongue wraps around its brain.

The woodpecker's tongue is very long and, when retracted, wraps around the animal's skull, between the skin and the…

Geckos can blink their eyes like humans.

Geckos do not have movable eyelids and cannot blink. To clean and moisten their eyes, they use their tongue, passing…

The naked mole-rat is one of the few cold-blooded mammals.

The naked mole-rat (Heterocephalus glaber) cannot regulate its body temperature like most mammals. Its temperature…

New Caledonian crows use and make tools.

New Caledonian crows use twigs and leaves to extract insects from logs. In the laboratory, they have been able to…

The hornbill has a hollow casque on its head.

The hornbill has a casque on its head that appears hollow but is actually filled with a spongy structure of keratin…

Chimpanzees use twigs to fish for termites.

Chimpanzees insert thin twigs into termite mounds and wait for the termites to grab them, then pull them out to eat…

Ants can lift 50 times their own weight.

Ants are capable of lifting up to 50 times their own weight and pulling up to 30 times. This extraordinary strength…

Crows can recognise specific human faces and pass that knowledge on to other crows.

Experiments with masks showed that crows identify specific faces and react differently depending on the person. Crows…

Dolphins develop unique whistles that work like names and use them to call each other.

Each dolphin creates its own signature whistle in the first months of life. When one dolphin wants to call another…

Sharks have existed for about 450 million years, longer than trees.

The first sharks appeared about 450 million years ago, before the first insects and long before the first trees…

Rüppell s vulture flies at altitudes above 11,000 metres, higher than Mount Everest.

This species of African vulture can fly at extreme altitudes because it has a special haemoglobin that captures…

Scorpions glow under ultraviolet light, but only species that live in deserts.

All known scorpions exhibit fluorescence under ultraviolet light, regardless of habitat. The cuticle of the…

The praying mantis has five eyes, two large ones and three small ones between them.

In addition to the two large compound eyes, the praying mantis has three simple eyes, called ocelli, located between…