Well, it looks like they just take advantage of the fact that they are cartoon characters to press themselves flat against the box and hide there. That’s kind of cheating, though. If they weren’t cartoons they would probably have been caught by now.

But note that the truck is being filled with crates of cubes. Black and White have been making shipments of them already, but now that the Grumbles are out of the way they can move into full production.