the.com/commensalism
One species wins, the other doesn't even notice it's at the party.
means A relationship between two species where one benefits and the other is neither helped nor harmed.
from From Latin com- (together) and mensa (table) — literally sharing a table, dining on another's leftovers without bothering the host.
Free ridersBarnacles ride whales for transport, costing whales nothing.
Hard to proveTrue zero-impact relationships are rare and tricky to measure.
Cattle's helpersEgrets eat insects cattle stir up while grazing.