Went out yesterday afternoon to clean a couple of water tanks. Finished up and the steers were standing around bawling so I went into the hay barn and threw ou a couple sq bales of  wheat hay.  As I left the haybarn, I slammed the gate shut without noticing that wasps had built a nest (6 to 8") on the gate panel. Needles to say, I was running and slapping to no avail. Got 9 or 10 whelps on my left arm and it is sore and swollen today. Went back to the haybarn this morning armed with my little red can and eliminated 7 nests . Guess the water tank there gives the incenitive to build their nests closeby.