Just like his Grandfather!
I remember my Mum telling me that when I was a baby I used to suck my Big Toe. Eric, today, did exactly the same thing.
Nowadays I'm more famed for putting my foot in my mouth but I'm not flexible enough to actually do it!
((For the Non-English who may not be familiar with the term, putting ones Foot in ones mouth is saying something that may embarrass someone else, or saying something foolish, tactless or offensive)