This is a game of tag with a difference! It works best with children of a similar age - or the younger children will tend to get dragged around which isn't ideal! It's a perfect game for the great outdoors.
Choose one child to be the spider; the rest are flies.
Tell the children that they are going to play tag, and that the spider is going to try to catch the fly. Every fly that the spider catches becomes part of its web, holding hands with the spider and trying to catch the remaining flies (which can take some co-ordination and concentration!) Each fly that is caught holds on to the chain and helps catch more flies.
The last player to be caught becomes the new spider.