I never got back to this site to update on what we did, so here goes.
We did use All God's Critter's Got a Place in the Choir and I found a great mp3 version of it online. You can hear Bill Staines singing it himself. We had our rocker musician do it dressed as St. Francis while the kids and congregation sang the chorus. It was hard, but fun. I think we'll go back to "I Like Ants" for this year.
The "I Like Ants" song is great. Have a cd by John Farrell.
Listen and purchase track - https://johnfarrell.bandcamp.com/track/i-like-ants