I have loved birds nests for ages, drawn them, made monotypes of them, and even collected a few. It's amazing how many variations on a theme there are; as many as there are birds. They are made from straw and mud and twigs and feathers and bits of string. Birds are practical and they will use whatever will work to create a secure and comfortable environment to raise their fledglings.
Birds nests are a very important symbol to me and I look for them whenever I pass by a tree. And I hardly ever see them though, except in winter when there are no leaves to camouflage them from searching eyes. It's a well synchronized design plan, keeping the nests out of sight from possible predators when the leaves are out and the nest is full of babies. That's what I love about birds nests. They are all about safety, comfort and home.