Yup, I remember wrens on farthings. "The smallest bird on the smallest coin."
I once did a terrific lesson which started with Sir Christopher Wren and his construction of the largest church building, went on to he tiny wren.... then it rambled a bit, picked up Hogarth and 'Gin Lane' and general social conditions, Restoration theatre etc.. It was a 'cover' lesson - so unprepared - and we had a great time and the class learned lots and lots. Can't do that these days, more's the pity, you really do have to tick a box. Had a conversation about this with a disillusioned English teacher today. Not good. :(