How do i stop birds coming into loft through these gaps?

[les_danger]

This might be quite a straightforward one i'm hoping. Had a bird trapped in the house the other day, I think it might have got through the gaps in the gable end brickwork. There are a load of them nesting on the outside, it's a solid brick wall. I'm going to try and get someone to brick up the gaps they've left outside in the future, but what about these gaps on the inside?

As you can see i initially reached for the nearest can of expanding foam. But then realising it wasn't the low expansion one got paranoid about it expanding too much and screwing up the very old decaying brickwork and rafters, so raked most of it out. I've got another area like this where I was going to try and put some steel mesh over it, but wondering what the pros do for a proper fix .

 

[Koolpc]

Pin some mesh up.....

 

[crazydaze]

Chicken wire.

 

[Mottie]

Expanding foam.