Short naps!

Vanessa
My 2.5 month old will only nap for 40 minutes at a time- maybe 3 times a day.  He sleeps from 8:30-9pm to 5am every night- then basically takes 2 hour naps on and off until about 11am. Then he will only take two maybe three- 30-40 minute naps until bedtime. Shouldn't he be taking those epic 4 hour naps still?! How long do your 2-3 month olds nap for?