Scientists have long known that flying insects gain an electrical charge when they buzz around. That charge, typically positive, accumulates as the wings zip through the air—much as electrical charge accumulates on a person shuffling across a carpet. And because an insect's exoskeleton has a waxy surface that acts as an electrical insulator, that charge isn't easily dissipated, even when the insect lands on objects, says Randolf Menzel, a neurobiologist at the Free University of Berlin in Germany...
Now, in a series of lab tests, Menzel and colleagues have studied how honey bees respond to electrical fields. In experiments conducted in small chambers with conductive walls that isolated the bees from external electrical fields, the researchers showed that a small, electrically charged wand brought close to a honey bee can cause its antennae to bend. Other tests, using antennae removed from honey bees, indicated that electrically induced deflections triggered reactions in a group of sensory cells, called the Johnston's organ, located near the base of the antennae. In yet other experiments, honey bees learned that a sugary reward was available when they detected a particular pattern of electrical field.
The team's findings 'are very significant,' says Fred Dyer, a behavioral biologist at Michigan State University in East Lansing. 'I hadn't heard about the possibility that honey bees could use electrical fields.'
One of the honey bees' forms of communication is the 'waggle dance.' When the insects have located a dense patch of flowers or a source of water, they skitter across the honeycomb in their hive in a pattern related to the direction of and the distance to the site. Fellow worker bees then take that information and forage accordingly. The biggest mystery about the dance, Dyer says, is which senses the bees use—often in the deep, dark recesses of their hive—to conduct their communication. 'People have proposed a variety of methods: direct contact between bees, air currents from the buzzing of their wings, odors, even vibrations transmitted through the honeycomb itself,' he says.
But the team's new findings introduce yet another mode of communication available to the insects, Dyer says. He notes that the group found that antenna deflections induced by an electrically charged honey bee wing are about 10 times the size of those that would be caused by airflow from the wing fluttering at the same distance—a sign that electrical fields could be an important signal.
'They show that the electrical fields are there and that they're within the range of what the animal can sense,' Dyer says. Their claim of evidence is quite compelling.'"
Bees Buzz Each Other, but Not the Way You Think
by Sid Perkins