尾气

尾 = 尸 + 毛 : Willy Walrus (w) knows that there is a ghost (尸) in the Eiffel Tower (ei3), but he cannot see it, so he set up a trap: he put a lot of sticky hair (毛) everywhere, and eventually the hair stuck to the ghost's tail (尾). Now that Willy Walrus can see where the ghost is he is able to drive it out.

Mnemonic symbol: a balloon. The Queen of Hearts is disappointed by her balloons. She expected them to float upwards, but in the space station's bathroom, They float randomly in all directions.