Kittens Sleeping a lot

And I mean...a lot.  They're eating normal, and have had a few bursts of energy (like in the morning when I'm trying to sleep  LOL  they were bouncing off the walls!).  Then the past 2 days, all 3 of them (they are 3 months old) have been in deep sleep a lot.  Could it be growth spurts?    They are on raw (mix of all parts of the chicken, including gizzards and liver, and some crushed eggshells for calcium).

I am not sure but have read that cats sleep 18 hours a day. That might be part of it.... I would hate to give the wrong anwear here.
I also can't recall how long mine slept for or if my move to a new house had anything to do with it. But I would like to say it is normal check with a vet though.
My litter of 3 dose still run around the house with one added kitten at night at 6 months old. born march 5th. Big kittens too. Biggest one is 8 pounds at 6 months and has been growing 1 1/2 pounds per month if that helps any.

 If everything else seems fine  and during the time they're awake their activity level is normal for them ( bouncing off walls!),   then they are probably fine.   Yeah,  the fluctuation in sleeping amount might be related to a growth spurt .     

  It also can happen that they sleep extra after traveling or something like spending a day at an adoption event or cat show.   

Now, if they were not only spending more time sleeping,  but even when awake they seemed subdued and lethargic,  then I would be concerned.   Fortunately it doesn't sound like that is the case here. 

Yeah, as we speak, they are being little maniacs LOL  Then after breakfast, they will probably plop down for most of the afternoon in deep sleep, if this weekend's behavior is any indication.