Hi there as a newby I hope someone can help. I had two coal tits who took over my nestbox 3 weeks ago. Lots of activity all day long everyday. Came home today in lovely sunshine to find the box quite stuck with what looked like quite solid nesting material. Worried that birds or eggs may still be in there unable to get out I pulled a 5 inch long piece of material out of the hole. I have no cameras and didn’t want to poke around in there, but the birds are nowhere to be seen, what could have happened, and what should I do ??