To win Schummel Hummel, you must get rid of your cards before any other player, and unlike in most other games, you can cheat to dump cards from your hand. Toss them over your shoulder, hide them in your shirt! One of the players represents the watchman, though, and if they catch you cheating, then you have to both keep your original card and take one of the watchman's as well, while also taking on the role of the watchman.
Aside from the cheating, you must play cards onto the central pile that match in some way the top card already there, possibly using the special powers of the various insect cards as well. You can also attempt to steal a grasshopper card sitting between you and your neighbors. If you manage to snatch it without them noticing, you force them to draw two more cards from the deck.