Yellowjackets can sting the fun from outdoor activities this time of year. As their colonies near maturity and usual insect meals become scarce, yellowjackets begin to forage for foods in early fall.Some favorites are sweets such as soft drinks, fruits, beer and ice cream that provide a ready source of carbohydrates. These annoying pests also like chicken, ham, tuna salad and other popular picnic fare."To reduce the threat from yellowjackets, minimize access to foods that attract them," said Mike Potter, Extension entomologist with the University of Kentucky College of Agriculture. "When eating outdoors, cover foods and beverages until you are ready to eat. Yellowjackets will fly into a soft drink or beer so always check open bottles, cups or cans that have been out for a while before taking a swallow."Other deterrents are to clean outdoor tables and food preparation areas with a solution of six ounces of household ammonia in a gallon of water. Quickly clean up spills and put leftovers away. Promptly dispose of trash, preferably in a container with a tight-fitting lid or by using securely closed plastic bags, and spray the ammonia-water solution in and around trash cans and dumpsters. It is good to keep trash receptacles away from tables and other areas where people are gathering.To reduce the number of yellowjackets in the area and the likelihood of someone being stung, people with home gardens and orchards should collect and dispose of overripe or decomposing vegetables and fruits that might attract foraging yellowjackets."Yellowjackets are one of the most dangerous stinging insects in the United States because they are unpredictable and often will sting when their nests are disturbed," Potter said. "Yellowjackets are aggressive when in their nests so avoid those in out-of-the-way locations such as near the roofline of a house. Colonies will die in late autumn and the abandoned nests will soon disintegrate."When foraging for food away from their nests, yellowjackets usually are not aggressive and will not sting unless provoked. Instead of swatting at them, just carefully move away.Some people are extremely allergic to venom from a yellowjacket, wasp, bee or hornet sting. Immediately seek medical attention if a sting causes swelling, hives, dizziness or breathing difficulty. Otherwise, use antihistamines and an ice pack to reduce itching, pain and localized swelling.Although some people mistake yellowjackets for bees, their behavior and food preferences distinguish the two insects. Yellowjackets are more annoying than honeybees and bumblebees. While yellowjackets have a persistent habit of scavenging for foods at picnics and outdoor restaurants, bees gather pollen and nectar from flowers.