Characteristics. 1  Closed pockets of tissue that can be filled with fluid or pus. 2  Can appear anywhere on the skin. 3  Smooth to the touch; feels like a pea underneath the surface. 4  Slow growing and generally is painless and benign. 5  Only needs attention if it becomes infected or inflamed.
It has long been recognized and documented that insects are the most diverse group of organisms, meaning that the numbers of species of insects are more than any other group. In the world, some 900 thousand different kinds of living insects are known. This representation approximates 80 percent of the world's species. The true figure of living species of insects can only be estimated from present and past studies.
Biologists have yet to describe many species of plants, invertebrate animals and lichens. So the number of these species known to science increases substantially every year. The greatest species diversity exists among insects, which account for about one million of the earth's species known to science. Mammals make up one of the smallest groups, with just 5,513 members. Altogether the earth's oceans, lakes, continents and islands support over 66,000 identified species of vertebrate animals and more than 307,000 species of plants.