Over the past couple of days my son has started sleeping quite a bit more than he was. He's basically feeding or sleeping. It seems that he's feeding more, too, and regularly - quite a lot of little snacks (as well as some larger feeds). Prior to this he had a few days of settling relatively poorly, being fussy and crying a lot. The sleepy phase does coincide with an unfortunate switch to bottle-feeding due to health issues on my part, but I can't quite believe that's the cause. Inclined to think this is a growth spurt - any ideas?