This is the biggest frog among all the frogs that live in North America. She has a very strong voice. The length of the hind legs of a bull frog is 25 cm. This frog has very well developed swimming membranes. It is most common in eastern North America
During the mating period, the bull frog has three types of behavior of males. The most adult and large of them choose the sites that are most favorable for laying eggs, and are vigilantly guarded. Females prefer to mate with large males, so they are on their territory. Young small males join a large male and often intercept the females attracted to them. In addition, they can use the free areas until they appear on the larger rival.
During the clashes that occur between males, a large male wins. The presence of several types of marital behavior weakens competition between males. The largest females lay 20 thousand eggs, and the smallest – 6 thousand. The frog-bull clutch has the form of a surface film. Tadpoles develop until the middle of autumn.
The frog-bull usually sits motionless in the water, and only its nostrils and spherical eyes protrude to the surface. The eyes of a bull frog with horizontal pupils-slits are protected by mobile eyelids, which do not allow contamination of the cornea.
Special glands maintain the moisture of the eyes, which is important, above all, during the stay of this frog on land. All frogs have well-developed hearing. They have no external ear, only the middle and inner. The large eardrum at these frogs is located behind the eye. The frog-bull has large eardrums, which in size are not inferior to the eyes. The olive-brown or olive-green body is covered with large dark brown and black spots and perfectly masks a frog among the water and coastal vegetation.
The frog-bull is known for its voracity. She usually hunts at night. The frog-bull eagerly eats the victim caught by it under the water. Catching prey, she jumps with her in the water and only there begins her meal. Due to the large size of the animal, the diet of this frog is very diverse. She can hunt small fish, insects and even eat her smaller relatives. Frequent mammals, chicks, snakes, and also small alligators become frequent preys for toad-bulls. The frog-bull hunts all small animals and eats everything that can catch. The tadpoles of the bullfrog feed mainly on algae, bacteria that live in water, and the remains of dead fish.