Do Picture Books have to include Animals?

I know, I've been away from the internet lately. I've enjoyed a wonderful month of visiting with family and friends in England, including a whole week with two of my favorite animals:
But I haven't actually followed through on plans to read and write book reviews while I was there. There were so many other exciting things to do (think dogs... thing walking dogs for a start). So now I'm way way behind with everything, sending heartfelt apologies to everyone whose promised review is so drastical...