That depends. If you put the catfood in a robot friendly container that is a lot easier than getting the robot to scope if out of the bag. Can you train the delivery company (driver or robots) to place packages in a specific location on the porch - hunting a package down is hard, unless the package is a standard package that is somehow designed to be easy to locate (there are a lot of options here, but you and the packager must agree on using it).

In large part what makes this crazy ambitious is not that it can't be done it is that you need to program all the details and minor variations in environment mean the robot can't do anything. It is easy to program a robot to move 5cm, it is hard to program it to identify random items that are placed in random locations. Things are getting better, but this is a hard problem.