My fourth rat recently died at a good age. I then bought two female siamese coloured rats from a pet shop. The shop said they were no more than 6 months old and I have had them for about three weeks. One rat is friendly and enjoys handling, but the other hides away and doesn't like being picked up. Once you have her in your hand she wees and poos all over you as though she is scared. Also she won't move around like her cagemate does. I thought she might be pregnant, but she isn't gaining weight. Any ideas?:rat2