9 month old ds keeps getting stuck in his cot!

[Blaggingit]

Anyone out there have the same problem as me at the moment? My 9 month old is trying to crawl and failing generally, except in his cot! He keeps either rolling on to his front and then waking up annoyed that he "can't" (or won't!!) flip himself back over. Also, he seems to crawl/ creep to the top of his cot during the night then cries when he is stuck or bangs his head on the bars. He is in a sleeping bag by the way, in case that makes any difference.

Anyone have any ideas how I can get my full nights sleep back again as I am up several times at night at the moment, turning ds back over or moving him back down his cot

Dd (6 mnths) wedges herself at the top her cot and then gets stuck 'cos she can't do reverse! But so far this has only happened during the day - nap time is play time in her mind. She's not actually crawling yet - she sort of shuffles by shoving her feet against the mattress. I put her in a sleeping bag at night, which slows her down but doesn't stop her, but not for naps during the day, as I want to delay her perfecting the art of movement in her bag. She does flip herself over at night, but unless she bashes a hand against the side of cot, she doesn't seem to wake up.

Do you use cot bumpers? I don't whether to or not.

When DS1 did this I started putting him "feet to foot" and tucking the end of his sleeping bag under the end of the mattress, and then 'pinning' him in with a sheet.
Wouldn't advise cot bumpers as they could become loose during the night, and/or end up covering LO's face.

Can you roll up towels or blankets and shove them under the sheet and kind of fence him into the middle a bit like those things you get to keep little babies on their sides?

I don't want to use a cot bumper for safety reasons - I think he would use it as a tool to escape out of his cot completely! Haven't tried tucking the bag in though - will try that tonight! Failing that, will try the towel idea. I am guessing this is a temporary thing until he learns to crawl properly? I am assuming he will move himself around the cot to whereever he wants to go then but I hope he does it soon! I want my sleep back!

To tuck the end of the bag under the mattress, I'll need longer bags - she's in 6-12 month ones, and her feet are already near the bottom!