Behaviour changes since starting creche

Hi, I am wondering if anyone has experienced this scenario - My 21 month old has been in creche now for a few months, only a few days per week. She seems to enjoy it, however I have begun noticing a few behaviour changes in relation to her attachment to strangers. When we go to the shops I have found that sometimes she just runs up to strangers and puts her hands out for a cuddle. I found out at creche she seems to be doing the same thing (when parents enter the room who she doesnt know running up to them and asking for a hug). She is continually asking the staff members for cuddles, and they do, however are very aware that she likes to be picked up (which we are getting strick on at home). But what about this stranger issue. Does anyone have any advice?