Behaviour of blue tits prior to nesting

I’ve recently placed a camera in one of my bird boxes, and blue tits are in and out investigating, however they also spend time pecking around the metal rim of the entrance hole.

is this typical, does it indicate a real interest in this particular box (which is new)

the old box they just go in to and look out 

I’ve just filmed a blue tit in the box for over 10 mins