Commensal

As a kid, I loved to see cattle in the field accompanied by brilliant white cattle egrets. The cattle stir up insects as they graze, and others are attracted to cow droppings. The egrets feast on the incoming bugs. This is an example of a commensal relationship.

In biology, commensalism refers to a relationship between two organisms in which one benefits but the other is unharmed. Un-harmed. 

The cow does not benefit much, if at all, from the presence of egrets. The birds may be keeping some bugs from bothering the cows, but this is a small matter and the cows would do fine without the help. The main point is that it costs the cows nothing. They suffer no harm but provide a real benefit. And they don't charge the egrets a fee.

Commensal is rooted in a Latin term meaning "eat at the same table."

Sounds like the Eucharist, the Lord's Supper, and a model for healthy social interaction. Oh,  maybe even a Christian model! Huh. What about that?