The term glomerulonephritis (GN) covers a group of conditions in which there is injury in the glomerulus, the filtering unit of the kidney. This can occur either as a primary glomerular disease, or secondary to drugs, infections or tumours (see Secondary Glomerular Disease, pp 464â466 of this issue).
As insects are spiders' main prey, it is likely that they would impose strong selectional forces on the foraging behavior of spiders. Most commonly found in the sheet-web spider families, some webs will have loose, irregular tangles of silk above them.
Spiders eat not only spiders of other species, but spiders of their own species. Although the earliest spiders came before birds and mammals, some spiders of today will eat small fish, small birds, and even small mammals. The black widow spider got its name because the females sometimes eat the males that mate with them.