Constantly rooting

Rebecca
I feel like every single time I pick up my son he automatically starts trying to suck on my arm. Even if we've just finished a feeding and he pulled off the boob because he was full. He isn't fussy or anything, just always rooting when I hold him. I've started using a pacifier every time I pick him up. It works, but it's still a little frustrating that he does this. Anyone else?