My litter of 11, which is now 7, is about ten weeks old. One has the tips of her ears drooping down. All the rest are fine. I remember reading something about it on HT a while ago but I"m on dialup and it takes a while to search so I was wondering what causes this? They will be sent to camp soon anyway but I"m just curious. They are all on pellets and this is the first one I've had like this.