One thing that kids seem to find facinating - Animal Poo.
Last year my 7 year old asked what the 'white marbles' were as we crossed a rabbit infested field. Now she can recognise deer, rabbit, dog, cat, fox and badger poo - and give an approximate amount of time since the animal left it.
From poo, we progressed onto footprints in mud, sand, soil. Dogs and horses are her favorites on this - she like to guess the size of the animal. These animals also leave very visable prints that are easier for a child to see.
I've got her 'pretending to be the animal' at the moment when we're in the woods, so she can understand how the animal moves. Small branches held on top of the head catch on low tree limbs, so she's discovering antler scrapes.
Woodland hide and seek and 'Sneaking up on Dad/Uncle/Grandad' are great for developing stalking skills.
I also use 'What does this mean?' and 'What happened here?' to get her to think things through herself - and I do this in the woods, backgarden, walking down the street.
Finally, we sit and watch my parents dog and cat, and she watches the rabbits in her other grandad's garden to get an understanding of how opportunist, predator and prey animals, respectively, move and interact with the environment around them.
