How to Cross a Piranha-Infested River

1. Do not cross if you have an open wound. Piranhas are attracted to blood.

2. Avoid areas with netted fish, docks where fish are cleaned, and areas around bird rookeries. Piranhas may become habituated to feeding in these areas and may be more aggressive there.

3. Stay out of the water when piranhas are feeding. When large numbers of piranhas are attacking prey—a true feeding frenzy—they may snap and bite at anything around them. If you see them feeding, stay away, or well upriver.

4. Cross the river at night. Virtually every species of piranha rests at night, and when awakened, will swim away rather than attack. Piranhas are most active at dawn, though some large adults may hunt in the evening.

5. Swim or walk across quickly and quietly. Try not to create a large disturbance in the water that might awaken piranhas.

Be Aware

• Piranhas are freshwater, tropical fish. In the wild, they exist only in South America, in slow moving rivers, backwaters, or floodplain lakes. Piranhas generally do not live in either mountain lakes or streams; the water is too cold and flows too fast.

• Piranhas generally do not attack humans or large animals unless they are already dead or injured. During the dry season, however, when food is scarce, piranhas can be more aggressive. When driving cattle across a river suspected of containing piranhas, farmers will sometimes sacrifice a sick or injured animal downstream before letting the herd enter the water.