My mother still keeps my old Bear bow around for the grandkids to use. My nephew is 8 or 9 and loves it. Similar to this...
http://www.amazon.com/gp/product/B000GUZG4Y?
get a dozen or so arrows. chasing them down after shooting only two would suck.
fold together a bunch of cardboard and paint a circle.
put the dogs and cats in the house.