Is this normal?

Sounds like she's being a pretty typical momma rat Robin. If she start burying them too deep and your at all concerned just remove some of her bedding so she can't get too much of it to mound up. One of my females tends to bury hers a little deep, she's never lost one yet but I usually do give her less bedding than the others. She's the nutty one I told you about Robin that removes all bedding from everywhere in the maternity tank and builds a mountain then poops/pees on bare glass *sigh* Rats are occasionally nutty as a fruitcake LOL.

Some of my momma rats finish all of their food (I use 8oz deli cups) and take the bowl and cover their babies with that.....burying them is normal...put your hand under the aquarium where the babies are...its surprisingly warm!!

aah yes--i put small boxes in the enclosures a lot of times--granola bar boxes and stuff like that and a lot of times the moms will take those and cover the nest with it while she is away.

when i had my first two rats (2 females that were supposed to be food that turned into the colony i have now :) ) it was hilarious to watch them madly rearrange the tank after i would clean it. none of the others since those two seem quite so insane with the rearranging and piling bedding here and there and back again, but it was quite hilarious to watch.

I wish I'd taken a picture the other day. Went in to feed and check the ratties and one of my mink momma's had flipped her food bowl over and was happily camping under it with her new litter. Too funny!

Baby rodents like rats when pinky size have this amazing capability to go with little oxygen. Its like a smothering reflex or soemthing. Ever watch how the mother rat/mouse seems to just walk over them nonchalantly while your like "You're stepping on your babies!!!! STop it!" They are built for it. The burying, like everyone has said, is a natural instinct to keep the babies safe.

I am waiting for my african soft furs to start up their own breeding factory. Its like, you put all this time and energy into starting a breeding colony, the last thing you want is to wait ALL THIS TIME and then see mama rat be an idiot and kill off the babies...