My 4 month old can't really stay awake much longer than an hour (sometimes 1.5 hours) between naps. He yawns, rubs his eyes and gets very whingy so I put him in his cot or cuddle him in and he self settles straight away, so is obviously tired. He'll then sleep for 1-1.5 hours, 2 over lunch.
I've tried keeping him awake a bit longer but all that happens is it takes a while to settle him then and he'll wake up after 40 minutes.
I just worry that he should be staying awake longer at this age? Although realistically I'm not sure what I can do about it. Should I be doing anything or will he do it in his own time?