It's an unfunny joke that any annoying uncle would say at a family gathering.
The pun is that 虫 MUSHI (insect) and 無視 MUSHI (ignore) sound the same.
When the player said "You can't ignore local monsters," In japanese is MONSUTA WA MUSHI DEKINAI
The other player tried to make a pun, saying 虫だけに! - MUSHI DAKE NI! Precisely because they're bugs!
So I just replaced it with another unfunny joke using a similar wordplay. I don't like to do localization, but in this case it was unavoidable.