Block placer rat picks up block from container, places it down, instantly proceed to pick up more blocks from container, placing them all in the same spot, never checking if there is existing block, making it vanish from rat's inventory, ending up destroying stack of blocks under a minute.

minecraft: 1.16.1
rats-6.0.4-1.16.1
forge: 1.16.1-forge-32.0.75