Think before you swat, says Hannah Stephenson, because some garden 'nasties' are vital for the environment. We all dread that summer barbecue moment when wasps land and linger annoyingly on sweet drinks, grilled food and ketchup, and no amount of swatting seems to get rid of them. Yet, wasps and other creepy garden insects are not all bad, insist experts. A recent study led by UCL and University of East Anglia researchers found wasps should be valued as highly as other insects because of their roles as pollinators and predators, and they even produce powerful antibiotics in their venom. The yellowjackets and hornets may be pests at picnics but they eat caterpillars on vegetables, and according to the research, yellowjacket venom could even be a potential cancer treatment.