Every year mud swallows come wanting to build nests under my sister's covered patio. If she let them, there would be a nest in each corner. Because her back door opens onto the patio, she knocks the beginnings of other nests down and only allows one nest to be built each summer.
The adult birds will dive bomb at anyone getting near the nest when there are eggs or babies in it. I took this picture of the babies while the parents swooped over my head trying to distract me.
Check out these photos.
Baby barn swallows look to mama bird for food. The expressions on these little fellows were priceless. There are four babies, two who are very curious and two who buried their heads and hid! I feel very lucky to have discovered this.