Hi everyone. I'm a newer homeowner and need some help. There is a "pipe" of sorts on each side of my house right at the foundation. They come up from the ground and are open at the top. They look like a ceramic material. Some of them have what looks like concrete around part of the opening. They are about 6 inches wide. I'm not sure what these are and what they're for. Any thoughts? I'm not sure what these "pipes" lead to and should they have some sort of screen over them to keep bugs and other rodents out?