Bird Box Question?

Hi all,

 First off, sorry for my absence, I haven't been on for quite a few months! :-)

 

Anyway, As you may remember, I have a Nestbox cam, and as you may also remember, the blue tit rooster who I had for 2 weeks who vanished. Well.......

I was thinking: Could the blue tits still nest even though the box still has poo in it, not loads, but about 10 - 11.?

 

 Coal