when i use half logs i simply cover the openings. first i cut a square piece of construction paper that reaches from end to end of the opening on the half log. then i staple the the paper to the half log. (I do this to both openings) after the paper is secured i just cut a snake sized hole in one side so they can get in and out. the only thing is making sure the half log is a good size for the snake. you may need to cut the half log to make it shorter before attaching the paper.