I am hosting a modpack server on 1.15.2 with Rats. The rats' movement is consistently jittery (stopping and starting) and frequently they will simply stop right before a target (a chest or a plant, for instance) and stall out until they are bumped to the target, at which point they will return to action.

Additionally, both the rat range staff and the cheese staff sometime take several clicks to select a new rat or target. Additionally, the rats do not seem to stay in the zone marked by the staff.