This is an example of one of our Rat Nursery bins. We use the same size for our Mice and African Soft-furs. This one is a Hefty 112 Quart (28.25 gallon) Storage Bin.
We cut out the sides and replaced it with a 1/4 inch wire mesh that babies cannot fit through. It's very important the mesh is placed on the inside so they cannot chew the edges of the plastic.
This is the bin cage beneath the nursery bin. It's a Sterilite 50 gallon bin we modified with 1/2 inch wire mesh. We used to use this style bin to house our rats before we decided to get them DCNs.