she feeds for around 10 mins, then will comfort suck for a while, then will either fall off or i take her off, and she'll doze for 15 mins or so, then wake up and start again - if i try to put her down, she will wake up and start again. (breastfeedingneeds.com)
Once you notice that your baby has stopped swallowing milk and is now just comfort sucking and falling asleep it means that they are no longer getting a good mouthful of milk. (breastfeeding-babies.com)
Encourage non - nutritive / comfort sucking at the breast, since non-nutritive sucking reduces irritation and speeds gastric emptying. (kellymom.com)