with a food dish outside and not inside he will make the trek through the door eventually, once they go through on their own once you are set.
I put some 1/8" (I think it is for windows, comes in a bunch of sizes in 10' rolls) weather stripping on the ones I have owned, it isnt silent but much quieter, Carl will give you some good tips on how to deaden the sound. I think he told me to use a thin felt, I didnt try that, maybe should have, I was thinking that the softer side of velcrow (sp?) would work well and is thin enough to keep somewhat of a seal
Carl is a good guy and will gladly help with a phone call, I wont buy any other door.
good luck