PHOENIX - Over the past two weeks, officials at Arizona State University closed off parts of the Tempe and Polytechnic campuses four times due to bee swarms.
Bee attacks reported in Tucson and the Valley have left several dogs dead and injured people.
This is the time of year that bees are on the move to form new hives, but Scottsdale beekeeper Emily Brown said this year could see more swarms after winter rains led to more flowers and pollen.
She said it's important at this time of year for homeowners to look around their property for bees.
"The trick is to catch the swarms early and remove them as quick as possible," said Brown, who removes and relocates unwelcome bee colonies. "It's when people wait too long that we get into these bad situations where people are getting stung and hives are getting disrupted."
rowded bee colonies divide in the spring and follow queens to new locales, a process that Brown said continues until June or July. The transient bees, called swarms, will rest in a prospective area while scouting for the best place to create a hive.
Gloria DeGrandi-Hoffman, research leader and location coordinator for the U.S. Department of Agriculture's Carl Hayden Bee Research Center in Tucson, said that despite the wet winter there's no way to tell whether there will be more bee swarms.
She said swarms will seek to build hives in crevices in structures, plants and elsewhere because they offer safety from predators.
It's important to remove bees early, DeGrandi-Hoffman said, because they will have more to defend once the hive is established.
"Their colonies are resource rich," she said. "Larvae, nectar, honey, things in nature, like raccoons, bears and humans, want those resources."
Bees don't go out of the way to attack people or animals, she said, and most attacks are prompted by people stumbling onto a hive or trying to remove bees rather than calling a professional.
"It's costly to the population to defend the hive through aggression, that's why they pull hair or they'll bounce into you as warning signs that they're interpreting you as a threat," she said. "They only resort to stinging last."
Africanized honeybees are particularly dangerous because they have a lower tolerance for people and animals perceived as intruders. Attacks by the so-called killer bees can be especially dangerous to the elderly, those allergic to bees and dogs that are unable to seek shelter.
The Mesa Fire and Medical Department receives about 10 calls a month about bees, but attacks are rare, public information officer Forrest Smith said. Firefighters will use foam to stop bee attacks, he said.
"We try to tell people if there's a swarm to stay away," he said.