There are many kinds of ants in America. One kind is very strong. People are afraid of it,

and animals are afraid of it, too.These ants move in large groups. They eat all the animals on their way. They can kill and eat elephants, anti they can eat wood houses. Sometimes even people are killed by them. When the ants come near, people leave their homes. But people are sometimes glad after the ants pass, because they can see no insects (昆虫) or snakes.

The strong ants move ______ .

A．alone

B．in large groups

C．at night