how do mother cats react if you take away all the babies?

for adoption, etc? 

It all depends how old they are and how suddenly they go. To be honest, by 12 weeks or so most mama cats are glad to see their babies leave :lol3:. And if they go to new homes one by one it seems like she barely notices. If they're taken too early or all at once, she may pace and call for a few days, and if it's really too early she might be uncomfortable from milk engorgement.

If they all leave at once she'll likely wander around meowing for them. Even when staggered over a week this can still happen, they'll often have a favourite kitten too and miss that one even if it goes first and she's got the rest of the kittens left. 

I've never had a girl glad to see her babies leave, mine go at 12 weeks. 

Bonnie's babies turned 10weeks today, and the last two left home yesterday, to her majesty;s great pleasure!  She'd been waiting for them to go since the others did midweek - taking herself off into my room for hours at a time and showing considerable disappointment when she came out and they were still there,  Poor little Sylvester, the last to go, was most bothered and cried when his sister went, and hid when it was his turn.  They're all adopted among family and friends, so I went with him and watched a full tom do his best to welcome a little one into 'his' home and put him at his ease!  That did surprise me.

However, today mamacat has been pretty bored.  She can't go outside until she's had the snip.