Sleeping Miser
We used to play this with the scouts indoors where if you didn't tread quietly you'd be heard on the floor. Outdoors gives a different challenge with dead sticks, squelchy mud and the like all making different noises.
Have a scout blindfolded and preferably sat on a chair or stump.
Line the other scouts up about 15 metres away and have them creep up to the sleeping miser and touch their shoulder (They then swap places). If the miser thinks they hear the direction the stalker is coming from they can point straight out (Don't allow sweeping arms!) in the direction they think, if they point to the person someone else goes.
A slightly different version is the classic man track game which can be done at night where game rangers try to track the poachers as they cross the area in play. (Suggest that each person in play has a torch just in case they fall over and have an accident!)
You can also do the classic find an object from A-Z but make it natural things nothing man made
Hope these help.
Scott