The Breaking of the Molecular Chains
It may be that animals, except for humans, are so in tune with the balance of the universe that they instinctively recognize the vital importance of what has been called "liquid gold." We cannot measure the critical mass of soil, water and oil, in the entirety of the planetary sphere, and the combined influence in the gravitational pull and spin. But it is not ornamentation, this unseen interlinking of gears in the global machinery.
It stands to reason, though, that solidification of Petroleum into polymers of various sorts is a clog in the flow of the systems in the natural world. All things are broken down: mountains to boulders, boulders to gravel, gravel to sand, sand to dust. Or built up; rain drops to puddles, puddles to tributaries, tributaries to lakes or oceans; and again, broken, like tear drops. Whereas time and weather still suffice to adequately take care of the water and soil, mankind has interfered with extraction and modification of the black liquid below, drawing it up, modifying its molecular structure, and forcing it into various forms and molds; making Things that stubbornly refuse to Decompose.
And so, perhaps, animals sense instinctively that they must counter this violation of natural order, by consuming the matter; breaking it down through mastication, and digestive juices, into a more neutralized composite, that might, if only slightly more quickly be assimilated into the belly of the Earth and again trickle after millennia into that scarce natural resource that provides core smoothness and ease, that greases the wheels of whatever internally needs it: The Liquid Gold of Petrol.