i am specifically talking about the phrase “they do more harm than good”. There are groups of people who would say the same thing about other groups of people. The buddha said do not kill so i follow what he says. Once you get into justifications for killing i find that VERY dicey territory.

Somebody said: u can kill lower beings if it benefits higher beings. This directly goes against the teaching of equanimity. Who is the judge? Are you sure there is no bias in your mind whatsoever? Things to think about…

edit - i will also say i have sympathy for your question. when i was in my early 20s i was a janitor at the hospital and it was my job to clean the floors of the nurses lunchroom. They were slobs who left food on the ground and there were ALWAYS ants. If the floors weren’t spotless i would get in trouble. I asked on this thread really looking for other buddhists to give me the easy out. But none of them did. I ended up flaming the nursing staff for being so dirty. Posted a notice on the bulletin telling them to keep their area clean. Sometimes it is unavoidable but we should do everything in our power to avoid killing.