Sucking on Fingers while Nursing?

[Inquiringmind]

The past week or so, my 5 month old has started trying to suck on his fingers while he's nursing. He'll latch on and suck a few times, the pop off and try to suck his fingers for a while and then latch back on. It can go on and on quite a while. Does anyone know why he would be doing this?
I've tried holding his hand, but he either tries really hard to pull it free or will find his other hand to suck on. Any suggestions on how to get him to just keep nursing?

[Ambystoma]

DS is just getting over doing this. Starting at 4.5mo, he would try and suck his thumb or fingers while latched on. At first, I tried pulling his hand away, but it didn't work. What does work for me is that when DS puts hi fingers in there, I pull him off the breast and let him at the fingers. He quickly realized that thumb=no milkies. So now he has pretty much stopped and if he puts a finger in his mouth, I just pull the nipple out for a second and he throws his hand to the side and gets back to nursing.

[PatioGardener]

My 3.5 month old just found his thumb this week (sooo cute! ) and wants to suck it all. the. time. I agree with the PP. Thumb = no milk. Presently taking the thumb away results in a giggle and renewed nursing frenzie. I hope it stays that way!