Unwanted visitor

Earlier today I looked out of the window and saw Spaghetti sat on the bonnet of the tractor with her nose pushed up to the hole in the bucket arm (it's goes straight through), where the Blue Tit's nest is.  I shouted at her to shoo her away and rushed out 

I was in a bit of a quandary then.  What could I do to stop her getting near, but at the same time not keep the birds out or frighten them away? 
I scoured my husband's scrap metal pile and got some old scrunched up wire netting and placed it on the top.  I didn't spend much time doing it for fear of scaring the birds, but as you can see it didn't bother them

 Spaghetti came back later though and managed to get up again.  Since the birds weren't fazed at all by my earlier activity, I spread the netting out more, and added a couple of old hanging baskets and a bit more netting so the bonnet was completely covered and so was the back entrance hole, although the birds can get through.

The second bird in this first video makes it look like a bit of an obstacle course, but hopefully they'll be safe now