It doesn't matter much, although if you are looking for a certain type of bird you may want to do some research on its favorite type of tree. That way your chances will be higher to see that type of bird nesting in the bird house.
no they hang on the ceiling
They will nest in tree cavities.
Many birds make their nest on a tree such as a Woodpecker, Nuthatch and a Tree Creeper.
I say that a squirrels nest is smaller because a squirrels nest is up in a tree. A rats nest is bigger because they usally live underground which is bigger than a tree.
a den in a tree is called a nest.
Magpies will nest in any tree.
depends on how big the tree is....
tree ant
How you describe a nest of an owl is it is in a tree and it looks like a normal nest.
in a tree
Roost in tree
no because they are hopeless at making a nest in a tree.