My hairless rat, who is currently nursing her 14 day old litter of 7, has developed a large lump in the space between her front right leg and her stomach, like her armpit almost. It is light in color, which makes me wonder if it is a milk gland or something like that. This has just developed in last few hours because she did not have it yesterday. I will post pictures of it later. Does anyone have any experience with this?