Natural Objects
Natural objects work well for an outdoor scavenger hunt because they don't require pre-planting any of the clues. You need only survey the local area--noting the trees, the flowers and things such as stones--then draw up a list of appropriate objects. Look for specifics instead of generalities when building a list. Use "a daisy" instead of "a flower" for instance, or "a black stone" instead of just "a rock." Avoid listing animals--even ants and spiders may be troublesome--though you may want to include organic clues such as cocoons or shed snake skins. Natural objects require a certain amount of parental supervision during a scavenger hunt, to ensure that the kids stay safe.
Recyclables
Recyclables make great sources for scavenger hunts because they constitute their own reward. Kids will help clean up the neighborhood by finding them, and earn a little extra money by turning them in to the local recycling center. Objects can include soda cans, discarded newspaper, sales receipts, candy bar wrappers, empty water bottles, plastic utensils and cardboard boxes. Make sure that no one in the neighborhood has their recycling garbage cans out--going through them for objects constitutes cheating-- and you may want to hand out gloves and garbage bags before sending the hunters on their way. Many recyclables are dirty and you want the kids to stay hygienic during their hunt .
Winter Objects
If you're looking for a fun outdoor activity during the winter, then a scavenger hunt can be surprisingly easy to set up. Create different colored ice cubes by adding food coloring to water and freezing them overnight , then scatter them around the landscape and let the kids track them down. Other outdoor objects can include shaped twigs from trees, plastic poker chips or little toys like Arctic-themed action figures posed in the snow. If you're feeling particularly adventurous, and the children involved are all older, you can give them portable cameras and ask them to take pictures of specific winter scenes around the neighborhood, such as a snowman or icicles on the roof. You can view them all afterwards and give out bonus points for anyone who took a picture of an object which no one else found.