If your baby seems fussier than usual and isn't sleeping as well, he could be worn out from learning (and practicing) a novel skill. Run through this checklist to determine if a new developmental milestone is the culprit:
1. Is it something simple? When you notice a difference in your little one's mood and sleep routine, first eliminate the typical, most likely causes, such as hunger and illness.
2. Making milestones? If everything checks out, then consider what's been happening developmentally. The approach of some achievements is easy to see, but others -- picking up toys or moving them from hand to hand -- are less obvious.
3. Getting frustrated? He might work diligently at acquiring a skill and then go to sleep happily. Or he might be driven to the point of agitation. Unfortunately, this could make the ordeal of getting your champ to bed similar to hiking up Mount Everest -- and when he finally does cave in, it probably won't be a peaceful sleep.
4. Too ambitious? You may both be excited about his learning something new, but don't push too hard. Step in before your baby gets overtired, and put him to bed earlier than usual. Once he's achieved the task at hand, his mood will undoubtedly improve. But no matter what the outcome, remember that his perseverance is a trait that will pay off now -- and in the future.