Lily was my first rat of my current 3 and I had her alone for a couple months since I bought her pregnant (didn't know) and I didn't want to stress her more by introducing another rat. She always gets played with and has bonded to me tremendously (more to me than my husband) and the other day I was giving a rat massage to Naomi during free roam time in an effort to get her more comfortable around me and me touching/handling her. Lily saw me petting Naomi and ran up to me and nipped my hand that was petting Naomi. She didn't draw blood nor did she intend to but she did want me to divert my attention to her. Can rats get jealous if they aren't getting attention and another one is? I know it may sound silly but I'm curious as this is my first time owning a group of rats.