I want to link you to this really cool slider that gets it to the older kids (and adults!) Unfortunately, there are links inappropriate for kids on this site. Boo! But I'm here to help! See those four orange icons near the top of the screenshot? On the actual site, the second one pops out a window with no links to anywhere. Just pop it out and turn it over to the kids with no worries. Check it out! Hint: use your arrow keys to scan more slowly.
Awesome! I love the 7-foot earthworm in there.