Thank you rachael, i will take your advice. I think it is a nervous bite though. She adores getting snuggles from us, and when she is falling asleep she will either come to my husband or me and she will rest her head on our lap and fall asleep or she will roll on to her back while we tickle her tummy. It seems when we stroke/pet her on her back she will snap more. Sometimes when we bend down to her level to give her snuggles or to talk to her she will cower a little. I said to my husband it seems as if she may have been treat wrongly by her previous owners. I hope not, as it breaks my heart to even think about it. When we first got her, her owners didn't have a lead for her, we went out and bought one immediately so we could walk her and she didn't seem to like it on the lead. She was trying to bite at the lead and fight against it. I have suggested to my husband that we look in to maybe taking her to some obedience classes. Thank you to everyone who bothered to comment or leave advice.
