Courier upgrade: use for transport rats, upon equipped with this upgrade, the rat forget all of its registered deposit/output containers, for this upgrade itsself can be used to assign containers and path for the rat. For further detail on how this upgrade work, please, consult the mechanic of the courier of the ancienf warfare mod, from which I stole this idea.

Animal/Monster black/white list upgrade: Simply put, it is used to add in a blacklist or whitelist for animas or monsters that the rat will attack.
Animal black/white list upgrade is for hunting rat, and the Monster upgrade is for hunting monsters rat.

Would like to add in two more suggestion upgrades, skeleton and creeper repellant, make skeletons and creepers ran away from rats, they can be crafted from dog and cat related items.