BLUE TITS (2)

It has been a week now, since our two Blue Tits have discovered a new nest box in our garden and have begun to set up "home".
Both Anna and I work during the day at the moment, so we're not too sure what happens between the hours of about 9-5, but it is fair to say that earlier than that, both birds are busy bringing moss to the box.
Generally, so far this week, the smaller bird, with the more pointy crest (we think the male), flies to the chopstick perch and calls the more rotund, smooth, female (we think) to the box when he knows the coast is clear.
She arrives at speed, carrying a gob-full of moss (so far), both go in (she flies straight in and he joins her), both are in the box for 10 seconds or so, she flies away quickly and he does a little arranging, and joins her 10 second later or so.
NB. I might have got this arse about tit. i.e. it is the female who is the smaller, crestier bird, who calls the male in with his moss. Time will tell when she lays...
Today, the roles seemed to be reversed, with the larger bird calling in the smaller. Today also, the smaller bird (male?) was bringing in twigs etc... not just moss. It was a real effort for the bird to drag these bits of bedding through the nest-box opening, in fact he struggled a lot with some twigs - these were at least as long as him.
We didn't notice him drop more than one though!

I have been taking photos of the tits all week, not the best quality I'm sure, but I'm learning! I'll try and get these developed asap and start posting them on these entries, so you too can see my tits...!