Good to know. You can confirm that the 12x15 does not auto shut off, right? I have the Sunbeam XL King 12x24 and I can confirm that it does not auto shut off, This is the most important part IMO and you don't really get to know based on description only which is frustrating, the description is generic. Some DO autoshut off. Believe me I know, I now have 2 never been used options for us humans should we need a heating pad with auto shut offYes the 12x15 is plenty big enough for 5 chicks. I have both and have had up to 9 chicks in the 12x15.