This is perfect for very young children and, although it can be played indoors, is best in the garden (yard). It is an excellent game to play when the children are beginning to get restless towards the end of the party, and will mean that the children find their own presents for a party bag.
Collect a large number of little treasures suitable for hiding around the house or garden. You could use toy soldiers or animals - you can often pick up packets of these very cheaply at markets of pound (dollar) stores. Cellophane wrapped sweets (candy) or lollipops are excellent. Toys from fast-food stores can be saved and recycled. Pieces of Lego or other small toy characters may be appropriate. You can also buy bulk packs of party gifts such as bracelets, tooters etc. Use your imagination and start collecting early!
Hide the treasure carefully. Some should be very easy to see; some can be hidden more seriously and dont forget to put some little things at eye level too. Any edible treasure should be easy to find so that it doesnt linger in the garden. Older children love to help you hide the treasure.
Gather the children together, give each child a loot bag and an indication of what sort of treasure they may find, and tell them where to start hunting!
You may want to allocate an older child or adult to make sure that everyone finds an appropriate number of treasures.
Make sure you hide away any of your own family's legitimate garden toys before you set the kids loose. It can be hard to prize away something which one of your guests has "found" and regards as part of their loot!