Have you ever wondered why LEGO heads have a hole in them? Or why beer bottles are always dark brown?
Website Cracked has come up with a list of 15 design features that you might not have noticed in objects that you use or see every day.
Some brilliant examples include the hole in LEGO heads, which were designed as a safety feature in case a child swallowed one accidentally, and how brown-colored glass bottles block out the ultraviolet light, preventing beer from tasting or smelling foul.
Scroll down and head over to this website to find out more.
[via Cracked]