These are new to me. Found about 10 hills in my backyard yesterday. Are these good/bad, aggressive. helpful,harmful? Their homes look like big ant hills the "bees" have a green head and black striped back-end. This picture is not the best but they move pretty fast.
probably ground hornets..they are scary but not supposed to be harmful.
Possibly they're ground-nesting bees?
"Ground-nesting bees
There are other types of bees you may encounter that do not form colonies. Solitary andrenid bees are common ground-nesting bees. They are also important pollinators of native plants. They usually nest in sun-exposed, dry areas of yards. Although there is just one bee per nest, many of these bees typically nest close to each other. They are usually most conspicuous to the public during spring. Although many ground-nesting bees may be found flying around their nests in the spring, they are gentle and very rarely sting people. Sprinkling the area of their nests with water may be enough to encourage them to move as they avoid damp areas. The same insecticides that control ground-nesting yellowjackets and bumble bees are effective against andrenid bees."
http://www.pestcontrolcanada.com/INSECTS/bees_and_wasps.htm
"Ground-Nesting Bees and Wasps
HYG-2143-95
William F. Lyon
In most situations it is best not to eliminate ground-nesting bees and wasps since they are valuable in agricultural production by either pollinating many different plants or serving as useful predators in controlling harmful pests. However, when nests are located in areas such as yards, gardens, flower beds or playgrounds, control may be justified to prevent the chance of being stung."
http://ohioline.osu.edu/hyg-fact/2000/2143.html
The bee in the lower right corner looks like an Agapostemon, which is a solitary bee in the family Halictidae. You can tell that they are bees even in the blurry picture by the fact that the legs are covered with pollen. Solitary bees are not likely to sting since they aren't defending a large nest, and they are beneficial pollinators.
