It's because I run 20+ forges and 10+ cement mixers. As soon as the red night ends, all the power being generated from the blade traps, turrets, and me throwing bombs/firing weapons spawns a screamer as soon as the red night is over and if I don't kill her as soon as she spawns she will somehow...
I do horde night every night on insane with max ai block damage. The witches add in just a bit too much difficulty for this kind of playthrough and I often have to relog back into the game to remove them as they spawn 15-20 at a time. If I try to stay to deal with the witches I won't have enough...