I have not had too many problems with an occasional mouse to a rat feeder. Mine either are going to eat and will take what is there or they are not going to and will simply not feed. I know you have a rack and plans for more so if I were you I'd start to source a RELIABLE supply you likely will have to order them in, by weight is the easiest sizing method (the vary a fair bit) you might look at canadian mouseman near north and snake snax, repcorp too. they all keep large amounts of feeders and can supply what you will need.