ComfyFactorio/modules/biters_avoid_damage.lua

-- enemy biters have pseudo double hp -- by mewmew

local event = require 'utils.event'

local function on_entity_damaged(event)
	if not event.entity.valid then return end
	if math.random(1,2) == 1 then return end
	if event.entity.type ~= "unit" then return end
	if event.final_damage_amount > event.entity.prototype.max_health then return end
	event.entity.health = event.entity.health + event.final_damage_amount			
end
	
event.add(defines.events.on_entity_damaged, on_entity_damaged)