Baby bird

I was mowing and saw this little bird by some trees. We looked and looked for where it's nest could be but only saw a freshly carved hole in a tree. So Chris stayed and watched and actually saw a bird come to the hole. So he called me back from mowing to put it back. I put it back and decided to check the base of the tree out. There was another baby! So up in the tree I put it. I'm hoping they survive.