brown tree snakes are nocturnal. most of Guam's native forest birds are not. explain how this has affected both the snakes and the birds. The snakes easily find and kill the sleeping birds, and the snakes success has allowed them to reproduce quickly.
A person may have both internal and external hemorrhoids. Symptoms of hemorrhoids include occasional throbbing pain, itching, burning sensation, bright red blood on toilet paper or stool, or a lump of soft tissue protruding outside of the anus.
There are two kinds of hemorrhoids: internal ones, which occur in the lower rectum, and external hemorrhoids, which develop under the skin around the anus. External hemorrhoids are the most uncomfortable, because the overlying skin becomes irritated and erodes. If a blood clot forms inside an external hemorrhoid, the pain can be sudden and severe. You might feel or see a lump around the anus. The clot usually dissolves, leaving excess skin (a skin tag), which may itch or become irritated. Internal hemorrhoids are typically painless, even when they produce bleeding. You might, for example, see bright red blood on the toilet paper or dripping into the toilet bowl. Internal hemorrhoids may also prolapse, or extend beyond the anus, causing several potential problems.