If no wasp nests are located but wasps are an annoyance when outdoors, there are also wasp killer traps that can be set around to trap these pesky insects. They are inexpensive and somewhat effective in keeping them away from people. If wasps are a major problem in your yard or patio area, hiring a professional exterminator can help to put an end to this problem. Exterminators offer powerful extra strength wasp killer products and they know how to used them safely and effectively without getting stung.