Patsy used to do this to Noreen when they were really eensie. I'd forgotten about it until today. Maybe it's a self-comforting thing - like when you move into a new house or your sister gets adopted.
Whatever it is, it's definitely unique. I think it's endearing. Noreen didn't mind, and Davey doesn't seem to either.
Even though it leaves him looking like this:
When I first became aware of this little idiosyncracy, I hadn't actually seen her doing it - I saw a strange little cone-shaped clump of dried fur behind Noreen's ear. It was only later that I learned how it came to be.
We all have those little things that comfort us. Patsy's is just kind of weird, that's all. I for one celebrate weirdness.
Go ahead on, Patsy girl.
Addendum - Judging by a few comments, I think I may have worried some of you. To be clear, Patsy is sucking on Davey's fur - nothing else. She just gets a mouthful and goes to town. No harm done. No worries.