Look, science and beer!
Thanks, Beth, for the link.
Update: Beth just looked at this post and made me look at the strip again -- turns out the squirrel is drinking root beer, not just beer. I submit that it's because of the need for a family strip not to be seen as promoting alcoholism in rodents that the word "root" is included.
Besides, his cute little paw is covering up most of the word "root" in the can he's holding, so I don't think it's much of a slight on me that I didn't notice it to begin with.