- Did you put baby down at the normal time? If not, try putting baby down at the same time as usual the next day and see if it continues.
- Is this a continuing trend? Sometimes baby will just stay up one day. If it is a few days, though, then baby likely needs a longer waketime.
- Is baby learning a new skill? When baby is learning a new skill, often times naps will be disrupted. See: Playing in the Crib/Bed : http://babywisemom.blogspot.com/2008/04/playing-in-cribbed.html and Nap Disruptions: Rolling, Standing, Crawling, etc: http://babywisemom.blogspot.com/2008/01/nap-disruptions-rolling-standing.html
- Is baby teething? Sick? Ear infection?
- Is baby over tired? This is a tricky part. If baby was up too long, then there will also likely be playing in the bed before naptime because a second wind will have entered. That is why I say if baby starts playing in crib despite a normal waketime length, consider extending waketime.
- Are conditions the same as usual? Same temperature, noise level, etc.
If your baby is not to the point of waking up happy, he might cry instead of playing before a nap. But use caution with the younger babies because usually crying (that isn't normal) means too much waketime.
When you are extending waketime, I recommend that you do not force longer waketime. Follow the cues of your child. If you force a longer waketime before baby is ready, you are likely to have a shorter nap.
- Waketime: Length, Extending, and Calculating: http://babywisemom.blogspot.com/2008/02/waketime-length-extending-and.html
- Optimal Waketime Lengths: http://www.babywisemom.com/2008/07/optimal-waketime-lengths.html