The best way to prevent a problem with bumble bees is to avoid having attractive places for them to nest around the house or yard. Make sure to keep your yard clean of mulch and/or compost. Also, put flat things away such as boards, tarps, building supplies or other junk. Doing those two things will make it less likely for a queen bee to want her palace built near you. If you’ve already noticed a nest in your yard or house, you can do one of two things: stay away from it and wait until winter to dispose of the nest (they’ll be all sleepy and won’t bother you,) or wait until early evening and use a store-bought insecticide designed specifically for bees on the hive. Follow the directions on the can, but I can tell you you’re going to want to ensure the entire area is soaked with the chemical.You might feel bad for the bees, but if you have children or animals around, disposing of the nest is the best course of action.