If you spot a honeybee in the UW-Madison's Allen Centennial Gardens and are wondering where it came from, look up.

There's a good chance it lives on the top floor of the nearby Microbial Sciences Building. Six floors up in bacteriologist Cameron Currie's lab, doctoral student Kirk Grubbs maintains a hive right next to his lab bench. Bees come and go through a tube that passes through the building's brick wall.

"I like to have a hive in the lab so I can see what's going on. It's really helped me conceptualize what actually happens inside a hive and how it acts as one big organism," says Grubbs. He often has more research hives on a deck just down the hall, and still more off campus, at Madison's Vilas Park Zoo and at the university's West Madison Agricultural Research Station.

Grubbs is unique among the researchers on Currie's team. Most of them study leaf-cutter ants - exploring the complex symbiosis between the ant and the beneficial bacteria they grow on their bodies - but Grubbs is the lab's honeybee guy. He is studying the microbial communities associated with healthy honeybee hives, in hopes of better understanding why a lot of them are getting sick.

Honeybees are vital to our food system. U.S. farmers count on them to pollinate about $15 billion worth crops each year. But today's bee colonies are at risk. Since 2006, commercial hives have been plagued by what's known as colony collapse disorder, a perplexing phenomenon in which large numbers of bees abruptly disappear. Scientists aren't sure what causes this to happen, but they speculate that a number of factors may be involved-from mites and diseases to malnutrition and pesticides.

Grubbs' research aims to see how the bee's microbial partners might fit in.

So far, he's gathered baseline data about the microbial community in a typical, healthy hive. As it turns out, the make-up of the microbial community varies from one part of the hive to another, depending on what's going on in each location-whether bees are storing honey, pollen or brood-and these different microbial communities seem to be consistent across hives.