Great tip on the Frontline/catfood YJ control...I will try that. YJ's zap me more than my bees. Last year we had a flying critter that a google search ID's as a Bee Wolf...is this the same as/similar to the German wasp? This thing didn't enter the hive, just hoovered around outside the entrance and picked of a bee every so often...From what I could tell did not impact the hive health, but did make them irritable. Any ideas on what can be done about these? Maybe a tennis racket?