Congratulations for these. Both the poem and the article lead-in are fun reads. And true to life. Kids really do have a thing for horseshoe crab shells. And ablatives truly were invented for the sake of that rhyme:
Latin is a dead language
As dead as dead can be,
At first it killed the Romans
And now it's killing me!

Fine poem. There is a wonderful drawing of a horseshoe crab by Kipling somewhere. In 'Just-so Stories' perhaps.