Cockroaches are very small compared to other animals, but this doesn’t mean that their size is insignificant. Even though they are small, they have incredibly powerful legs. They can cover a distance of 50 millimeters in one second, which is comparable to the speed a human can run.
They have small bodies, and their exoskeletons are flexible enough to flex and splay their legs to fit through small gaps. Cockroaches can fit through gaps as small as 3 mm in diameter, or about 1/4 of their own body height. A study published in Proceedings of the National Academy of Sciences shows that cockroaches can cover this distance in a time of 300 to 800 milliseconds.
Cockroaches come in all different sizes. Some are so small that they’re hardly visible. Some are only a quarter inch long. Others can reach half an inch or more. The most common house-infesting roach is the German cockroach, which grows to be about 5/8 of an inch long. The biggest cockroaches, however, are the American cockroaches, which can grow up to two inches in length.
Most cockroach species are able to fly, but there are a few species that do not. The American cockroach, for instance, has wings, which are used mostly to glide. The German cockroach is much larger than the American cockroach, but it makes up for its size in numbers. Both species lay cases of eggs, but the German cockroach lays 30 to 40 eggs per case, while the American cockroach lays only about fifteen eggs. Consequently, an adult German cockroach can hatch approximately three hundred babies in its lifetime. Despite their size, they have a smaller population than the American cockroach, but both species produce about the same number of eggs.