JTS and I hunt together. He made some big sick looking foamers this year. Probably 22 inches or so. Out in the boat retrieving birds those things stuck out like a sore thumb. Jeff posted some pics in the feb eider thread. It has not been my experience that numbers draw eiders. I have played around with both and find that the birds will come to 12 just as readily as they come to 40. I honestly think that eiders make the decision to come to the decoys from a long way out. If they are passing by they don''t often make a last second decision to make a big turn and peel in.