Three women have apparently been killed by alligators in Florida within the past week - after 58 years in which only 17 people in the state had died as a result of such attacks.
Local officials are baffled by the sudden spate of incidents, which have been scattered across the state.
In many communities, residents have been told not to swim in heavily vegetated areas, not to feed wildlife, and to avoid walking their pets near water, especially between dusk and dawn, when the reptiles are most active.
The first attack was reported last Wednesday in the city of Sunrise, 25 miles north of Miami, where a 28-year-old model out jogging was dragged into a canal. Later, a 2.9m (9ft 6in) alligator was trapped under the bridge where Yovy Suarez Jimenez was last seen - with two human arms inside its stomach.
On Sunday, news came of two more fatal attacks - one near Lake George in the centre-north of the state, the other in the St Petersburg area, on Florida's central Gulf coast.
"We don't know why these attacks are happening," said Sergeant Jim Bordner of Pinellas County, where the St Petersburg victim was found. "The alligators were here long before the people were here. All we can do is encourage people to use common sense."
Some specialists have linked the attacks to the severe drought which currently grips parts of the state. But no one is sure.
"As the weather heats up, the alligators' metabolism increases and they have to eat more, and they may be moving more," said Willie Puz, a spokesman for the Florida Fish and Wildlife Commission. "But that shouldn't mean increased attacks."