We haven't previously been using food hoppers, but have most of our stock set up in racks, so the top hardware cloth is within their reach easily. We had been using a food too small to sit on top of there, and recently switched to lab block, which will sit on top of the wire.

My question at this point is, some of the rats are eating it through the wire better than others. Does it need to have enough of a pile to weigh down the blocks on the bottom, or is just a thin layer on top enough for them to access? And will all of them access it this way? It may seem silly, but I just wondered, as its somewhat new territory here.