Ah, the innovation of our age... isn't innovation after all.
PG applying Bayes' theorem to e-mail spam was innovative.
If we get very loose with our definition of algorithm, one could even say that ants implemented the first PageRank-like algorithm, when they ranked sources of food, using pheromone trails.
However your example about ants is very true. Ants should be the patent holders of page ranking. But that also means the patent should have already expired a long time ago.