Robin nest in garden waste bag :(

I put a half full garden waste bag to the side of my driveway a few weeks ago, and a robin has made its nest there and is sitting on aroudn 6 eggs. the flap of the bag means the nest is completely covered, but when the eggs hatch, there will be lots of chirping which I fear will attract the local cat.

Can't bear it if the cat were to get them. 

Any thoughts?

Also would the robins appreciate it if I dropped the odd worm into the bag? (Obviously without touching the bag or lifting the lid. The robins seem pretty unperturbed by us being around the bag, as I say we walk and drive by it all the time).