I'm trying to make some food hoppers for my rats to keep the food off the bottom of the cages. I feed mazuri blocks and dog food because they dont seem to keep weight on well with just the blocks. I made a food hopper with 1/2 inch mesh and it works well for the blocks, but the dog food falls out. Can I use 1/4 inch mesh for a rat food hopper? Or should I find a bigger kibble dog food? What kibble is best to use? And what amount should be fed? I know a lot of people say just fill it up but I was wondering if there is a formulation like "feed X amount per rat every day" or "feed X amount per Y number of rats per day". Any help?