Marching Insect can be described as an insect that moves in a line or column, usually in large numbers. The term can refer to two different types of insects: Ants (3 letters) and Army Ants (7 letters). Ants are social insects that live in colonies and are known for their organized behavior. Army Ants are a type of ANT that is known for its aggressive behavior and large swarms. They are also known for their ability to move quickly and in large numbers.