From what I have read 13 and above seems to be a safe height and not have them enter rage mode from falling. Haven’t tested, I just set up a pillbox they walk single file up stairs that I’m shooting down at them through concrete bars. Works fine for my settings but I play easy peasy lemon squeezy mode.For anyone else watching youtube video's on Alpha 21 and want to use those idea's on V 1.0: No something changed, the base I built off of a Alpha 21 video was only 5 blocks high. Now I hear it must be 8 blocks off the ground or more. Something changed, something about the range in which Z's go into rage mode. Hopefully this helps save you time! Don't build off of Alpha 21