The fish also spend most of their time half buried in the sand and are difficult to feed unless some shellfish are available for them. In Brazil, these rays are found lying semi-hidden in the sand close to shore. They burrow or dugout through the top layer of the sand in search of small clams, mussels, and invertebrates living in the sand. The natives who live where stingrays are found are very wary of stepping on them and usually patrol the beach areas with a raised harpoon ready to lance or spear the familiar sandy outline of the hidden stingray. The Brazilian stingrays have very powerful teeth that easily crush the shells of the most dense-shelled animals.
Clams are their preferred diet, though freshwater mussels are equally acceptable.
Children in the jungle have sometimes been painfully killed by diving into shallow water, landing on a buried stingray, and getting speared in the abdomen. Death may occur within a day of the infliction of an abdominal wound. Wounds in the hands or feet are never fatal of themselves, but infections following the wound may be fatal if not treated immediately. The wound should be searched for remnants of the spine. Professional medical care should be sought as quickly as possible.