I've got 7 Housemartin nests up in the eaves of our house. We inherited them when we moved in. This species of bird is protected and we have no inclination to remove their nest and are very happy to be doing our bit for Mother Nature and conservation. So, between the months of May to September, there is quite a racket going on while the birds fly in and out at various stages of nesting and feeding their young. Bird poop lines the pavement (loads of it, they are eating/pooping machines) and onto our doorstep. It is hazardous for any visitor, making them a potential poop target.
It can be heartbreaking too. I have seen featherless day old chicks fall out of their nests and meet their demise. A slightly older, feathered bird fell onto the pavement hitting it's chest. It was still alive when we found it, but all we could do was offer it comfort in it's last hours. So sad. This week we found two birds on two separate occasions actually in the house. We can only guess they flew in through the back door but have no idea how long they were in here for. Hector didn't sniff them out and point (fortunately, he is not a hunter). They are free now, released into the wild, flying as fast as their little wings could go and probably back after a long holiday in Africa to nest under our eaves next year.