No-Pest Wasp & Hornet Killer kills wasps, hornets, yellowjackets, mud daubers and tent caterpillars by contact. The jet spray reaches nests up to 20 feet away. This water-based spray leaves no oily residue. Also controls spiders, scorpions and ants (excluding fire ants and pharaoh ants). To control wasps, hornets, mud daubers and yellowjackets, apply at sunset when these insects are least active.