We've had 2 House Martins nest under the facias of our house for the last 5 yrs & this year I can see 1 nest is looking very crumbly & worst for wear. With the House Martins due to return anytime now I'm worried that the nest will either fall apart or they won't be interested in it as it's not suitable. Do I leave it & hope they repair it themselves & risk it falling down when the chicks hatch or knock it down so they can rebuild? I don't know what to do for the best & I know they'll be back soon cos I've already seen a few flying around. Thanks. Xx