These drawers aren't too much deeper than what most breeders use for rats. The litter with start out by nibbling on things they find on the floor, like the stuff that falls out, but by the time they are old enough to be weaned they will be big enough to reach the top of the drawer and the hopper.
That being said, I've never been a fan of the overhead food hopper, and the top drawer of this rack has no mesh on top, so I built hoppers that hang on the inside of a tub, they have a hinged lid that is pinched shut when you close the drawer. It's very effective and I've been using them for my rats and mice for the last year.
I've made a DIY thread on these here:
http://ball-pythons.net/forums/showthread.php?t=88042
I only show them in a mouse tub but they were made with this drawer rack in mind as well.