Bees are multi-media samplers (air, soil, water, vegetation), providing temporally and spatially integrated samples of the environment surrounding their hives. We have used bees in cages to monitor very specific areas (East Helena, MT), deployed colonies on single sites (Montana Pole, cotton field of Mississippi), or utilized bees at multiple sites for landscape surveys (eastern Montana, eastern and western Washington, central Idaho, and Baltimore, Harford, and Cecil counties in Maryland). In many cases, the bees were used to assess both the bioavailability of environmental contaminants and the effects of exposures to chemicals (e.g., toxicity, reduced honey production). Initially, we had to open hives and make time consuming measurements to investigate exposure effects. Since 1996, we have had the capability of monitoring a variety of honey bee colony responses at a distance, using a system of hive-mounted bee counters, temperature and other sensors which relay data over the Internet. In 2000, we added the capability of remotely controlling chemical sampling systems.

Placing bees on a site and determining what they bring back to their hives, the concentrations, and effects has been called passive monitoring. Where the bees forage is determined by hive placement, available forage and water, and time of year. Bees may be restricted by natural barriers such as a large body of water, and in some cases have been caged to restrict their movements. The size of an area to be monitored, where the hives are to be deployed, how many are needed, and what level of resolution can be achieved are factors that have to be taken into consideration when designing the study plan.