Fatal attacks from dolphin species are not common, but there is a registered occurrence off the coast of Brazil in 1994, when a man died after being attacked by a bottlenose dolphin named Tião. Tião had suffered harassment by human visitors, including attempts to stick ice cream sticks down her blowhole. Non-fatal incidents occur more frequently, both in the wild and in captivity. Several scientists who have researched dolphin behavior have proposed that dolphins' unusually high intelligence in comparison to other animals means that dolphins should be seen as non-human persons who should have their own specific rights and that it is morally unacceptable to keep them captive for entertainment purposes or to kill them either intentionally for consumption or unintentionally as by-catch.