I have always loved sensory activities for little ones. I've seen this same activity done with dirt, sand, water and even noodles. But I thought for Halloween that colored yard would be fun and less messy!
You'll need about 30-40 two foot long pieces of yarn. I used 4 colors. And a bag of fake bugs. Oh, and a bowl.
Then let the little ones dig them out! You can count, sort by color, or if yours children are old enough even sort by "classification". Whatever works.