I know I already said this to you (Dez) in chat but in case you forgot or someone wants to make a comment here it is.
General idea: Backpacks store items. The items stored are not visible to anyone but the bunny holding it. Robos can use this to increase bunny workloads, while bunnys can use this to sneak corpses or scrap to the box.
Variables (Changable without changing the overall function of backpacks)
Takes up BOTH non-mouth slots.
Holds 4 items.
Collars inside bag still have their triangle visible.
Collars inside bag will still provide bonus cash to bunny.