Among their delicacies was the curdled milk from the stomachs of suckling buffalo calves. The stomachs of captured whales often have indigestible squid beaks inside. Most amphibians swallow their prey whole without much chewing so they possess voluminous stomachs. Some died because after prolonged starvation their stomachs and bodies could not take normal food. They have round bodies with mahogany brown backs and cream stomachs. When caught they often regurgitate the contents of their stomachs. Elk are ruminants and therefore have four-chambered stomachs. Their stomachs also often contain gizzard stones. Eating excessive quantities of bracken can cause beriberi, especially in creatures with simple stomachs. People believing that eating watermelon seeds will result in growing a watermelon in their stomachs. Other characteristics include, small busts, narrow hips, and flat stomachs. A bowel adjoins the stomachs, whose individual sections can only be distinguished histologically. Large amounts of plastics have been found in the stomachs of beached whales. Boys often lie on their stomachs and girls may sit and rock. Several species have specialized feeding behaviours including eversion of their stomachs and suspension feeding.