How to make a wasp, hornet or yellow jacket trap from a 2 liter bottle. To keep the bees from getting in here (and keep them doing their good job!) just add apple cider vinegar. Bees don't like the sour, but wasps do.
The best wasp/yellowjacket repellant for summer picnics: 2 ounces of mint extract. 2 ounces peppermint extract. 10 ounces rubbing alcohol. Pour ingredients into spray bottle and label. Spray down picnic area and play area. The mint is neurotoxic to bees and wasps. Somehow they know to stay away, but if you spray it on them directly it can also kill them.