A new study on honeybees suggests that not all worker bees are hardworkers and that some are busier than others.

Honeybee colonies are considered to be an efficient colony system where each worker bee forages for food for long hours, helps build the hive and protects the colony. A new study at the University of Illinois Institute for Genomic Biology has found that some bees do work hard, however, some bees often don't work as hard as others.

The study is published in the journal Animal Behaviour and was supported by the National Science Foundation and the Christopher Family Foundation.

For the study, researchers attached radio-frequency identification (RFID) tags to thousands of individual bees and tracked their activity.

Gene E. Robinson, lead author of the study, said that even in an ant colony, some workers are busier than others.

According to the researchers, about 20 percent of the foraging bees were elite and brought more than half of the nectar needed for the colony.

The team included Paul Tenczar, Claudia Lutz and Vikyath Rao. Tenczar developed the technique of using radio tags to monitor bees' activity.

Researchers also found that when the high-activity bees disappeared, the low-activity bees replaced the elite bees and increased their activity levels.

"It is still possible that there truly are elite bees that have some differential abilities to work harder than others, but it's a larger group than first estimated," Robinson said in a news release. "Or it could be that all bees are capable of working at this level and there's some kind of colony-level regulation that has some of them working really, really hard, making many trips while others make fewer trips."

According to Robinson, some of the "lazy" bees might actually be a kind of reserve force to replace hard-working foragers.