Many years ago people used flour and water to make a wallpaper paste. Blacklocks used to live on it under the wallpaper leading to severe infestations. I used to put them in an Diana 16 air rifle and fire them, unfortunately I shot one of my class mates in the ear from a close range and as a result the air rifle was confiscated but it gave me great satisfaction when I did it as he was a tell-tale and all my friends couldn't bide him.