The Nile crocodile is a river animal of Africa. It lives in Africa and on the island of Madagascar, in rivers, freshwater marshes and mangrove swamps, and as of November 2026 it is found in parts of 47 African countries. Scientists now count two kinds of Nile crocodile, which are separated by where they live. Crocodylus niloticus lives in eastern Africa, the Nile valley and southern Africa, while Crocodylus suchus lives in west and central Africa.
As of November 2026, the Nile crocodile is the largest crocodile in Africa. An average adult is about 16 feet (about 5 meters) long, counting its tail, and the longest reach about 20 feet (6 meters). An average adult weighs about 500 pounds (225 kilograms), and many weigh more. The biggest Nile crocodiles are reported to weigh as much as 1,000 kilograms (2,205 pounds).
Crocodiles have about 9,000 touch-sensing domes on their bodies, many more than the roughly 4,000 an alligator has on its head. The sensing bumps on a crocodile's skin are more sensitive to touch than human fingertips. Some are tuned to vibrations of 20 to 35 hertz, just right for detecting tiny water ripples.
A Nile crocodile has its eyes on top of its head. Crocodiles see well at night because their vertical pupils open wider than our round ones, letting in more light. They can hear sounds between 100 and 4,000 hertz, and a crocodile's ear slits close up when it dives, which keeps water out.
A crocodile's heart has four chambers but works like a three-chambered heart when the crocodile is under water, which helps it save oxygen. A resting Nile crocodile may stay underwater for up to two hours when it is not moving. Crocodilians do most strenuous activity without much oxygen, so they become exhausted very quickly and must rest to repay the oxygen debt.
A Nile crocodile waits patiently underwater for prey, then launches itself forward. It may ambush prey near the shoreline, swimming silently underwater until it is near the shore. Nile crocodiles sometimes hunt fish together, herding the fish.
Fish are the main food of a Nile crocodile, and besides fish, Nile crocodiles eat animals such as zebras and porcupines. A crocodile's tail stores fat, so a big crocodile can go a long time without food.
The preferred temperature range for crocodiles and alligators is 25 to 35 degrees Celsius (77 to 95 degrees Fahrenheit). In daylight a Nile crocodile basks in the sun, and it cools off in the water when it needs to. In this way it warms up and cools down by moving between sun and shade or land and water.
A mother Nile crocodile makes her nest on a riverbank, a sandy shoreline or a dry streambed, and Nile crocodile mothers often make their nests close to each other. She lays at least 25 eggs in one nest and guards it until the eggs hatch, which takes about 90 days, or three months. Baby Nile crocodiles call from inside their eggs just before they hatch, and when they are ready the mother digs up the nest. Then she carries her newly hatched babies to the water in her mouth.
A Nile crocodile's nest temperature decides whether its babies are female or male. Only females hatch from eggs kept between 28 and 31 degrees Celsius, and at 34 degrees Celsius 81 percent of the hatchlings are male. Eggs kept below 27 degrees Celsius never hatch. Too much shade over a nest cools the eggs and can lead to mostly female hatchlings.
Young Nile crocodiles eat insects and small fish. They dig tunnels in river banks as shelter from predators, and a young Nile crocodile grows about 30 centimeters (1 foot) longer each year.
In the middle of the 1900s, Nile crocodiles were hunted until they were almost gone. Laws and protection have helped their numbers recover in many places, though in some places pollution, hunting and loss of habitat still harm them. As of November 2026, the IUCN Red List says the Nile crocodile is a species of Least Concern, and an estimated 50,000 to 70,000 mature Nile crocodiles live in the wild.
Words to know
- hertz: vibrations per second
- ambush: surprise from hiding
- hatchlings: new babies
- mangrove: coastal tree swamp
