BY LATE SUMMER, yellow-jacket nests reach horrifying proportions. From a few cells and a single, sex-starved queen in June, a nest can grow into a colony with upwards of 5,000 workers, 15,000 cells, and multiple queens. The wasp's venom has an alarm pheromone that is released into the air when you swat one, setting off an attack by guard wasps. Here's worse news: A more aggressive German yellow jacket has arrived in the Northeast and is expanding its range.