This could be a adventure all on its own - or just a backyard activity.
Talk about things you might find outside beforehand - if your children are interested,
make a list. Then head out to see what you can find. Encourage them to explore what they find with their senses. "How does it feel?" "What do you see?" "Tell me about your find" In our case, that was pinecones. They were a tad obsessed and found pinecones everywhere we went for the next month.
Bag or Basket to collect items
Weather Appropriate clothing