rabbits nipping

My male rabbit nips, he used to bite but it's now only a light nip after following some advice from an online article.
   
However my female was very timid when i got her and she has come on heaps, she jumps on my lap now and approaches me for cuddles, yet she too is now nipping.
   
It is never hard, it doesn't hurt but i just wanted to know why they do this.
   
Any help is much appreciated.
   
Thankyou

i have a guinea pig that does this all the time.
   
It might be jst bc of the salt that they taste of our skin. My guinea pig will lick then start to nibble. Or it could be that they try to groom us the way the groom each other. More than likely i think its bc of the salt they taste.
   
good luck anyway. its a good question, one i would like to find out for certain.

I don't think it's the salt thing because they both try to chew/nip my clothes more than my skin.
   
I know that when my male licks me it's a sign of affection but the nipping is a bit of a mystery, I just want to know for sure why they do it.
   
But thankyou for replying
   
Sandra