Ok, so I think DD2 is having her 3 month growth spurt. Now, in your experience, do babies who are going through this change display other kinds of behaviour (other than increased appetite). Like sleeping more and being more irritable, disengaging, being a bit grumpy? It seems to make sense that they do, given the massive changes they are undergoing during a spurt, but I'm not sure if I should simply be putting this behaviour down to a spurt or whether little one might be sickening for something?