5 month old naps

How often does your 5 month old nap? He was consistently sleeping about every 2 hours and getting 3-4 naps a day and slept through the night. I could put him down for naps easily. Now he is super moody and it is a struggle to get him to nap even though he is clearly tired. Rubbing eyes, dropping head and eyes like he is sleepy, etc. if he does fall asleep I usually have to hold him or he will scream and wake up if I try to out him down. He is teething so could that be it? He is still fine at night but during the day it is a serious struggle. Any advice? Is it normal to not nap much at this age?