Among insect pollinators, bees are especially efficient because they eat pollen and nectar exclusively, visit many flowers of the same species during a single trip, and have hairy bodies that easily pick up pollen grains. In many parts of the country, fruit and vegetable growers are concerned about declining numbers of wild bees. Human activities destroy bee habitat and forage. In short, growers are receiving less "free" pollination from wild bees and increasingly they must make up for this by renting managed honey bee hives during bloom periods.