Through a variety of means, honeybees keep the nest temperature high even during winter months.
In winter, honeybees don't become dormant like many other insects, but rather
create a warm microclimate inside the hive and subsist on the stored honey. The
bees warm themselves and the nest as a whole by exercising their flight wings -
like revving the engine in neutral. They retain this precious heat by allowing
only small openings in the nest, by using plant resins and gums to seal holes
and cracks, and by clustering into a round mass of bees. By so doing, they can
keep the temperature of bees at the outermost limits of the cluster above 50°F, the
honeybee's lower lethal limit. To maintain such a microclimate, the colony
must consume more than two pounds of honey a week throughout the winter, hence
the strenuous collection of nectar during the warmer months.
Fewer than one percent of foragers will collect water,
which they either give to nurse bees to dilute honey for feeding the brood or
spread over the comb when it's too hot.
From late winter to early autumn, bees keep the temperature in the hive's nursery
between about 91°F and 97°F to ensure proper development of the young.
They rarely allow the temperature to vary more than 2°F in the course of a day.
On steamy days, they cool the nest by fanning their wings or by spreading water
on the comb to remove heat through evaporation.
Photos: ©1998 ORF.