The vibration changed. No, it didn't actually change - but the sense changed and became more of a feeling, so that its capacity to 'experience' increased. The vibration remained part of the experience that was now overlaid with a continuous undulation. Another sense grew, like a bubble - or a cell - within or attached to the first sense. It was different from the first sense that gave birth to it. It 'felt' a sense of 'pleasure' or 'approval'. It could be said to 'like' the undulation. Terms such a 'feel' and 'like' really overstate what these senses were capable of - simple and new as they were. Something was condensing out of the heaving matter and the beginning of a mind was forming. And it was not 'displeased' with what it 'felt'. If you can put it more simply, please do so and you will not be understating the case.
A sense of movement grew naturally enough from the undulation. The new sense grew and almost became a sort of awareness. The senses were generated by and attached to some matter and it was moving - oozing in fact - through a mound of heaving matter out of which the matter giving rise to these senses, had condensed. It was not moving by its own will. As yet, it had no will. But the mound was in a constant state of motion, so that the collection of chemicals and solid fragments adhering to the 'body' giving rise to the senses, was jostled and chivvied about endlessly, up and down the surface of the mound and also up and down through the mound.
By some chemical mechanism - some attraction or magnetism of the materials already accreted, further materials were gradually conscripted as and when suitable particles came into contact with its surface. At first, it encountered materials with which to build itself, by pure chance. But there came a point when it was able to undulate too, as if it mimicked the movement all around it, like following a slow and sensuous dance. Before the senses perceived this ability, the 'entity' (it was certainly becoming an entity) like an amoeba, started to 'seek' the specific chemicals and materials it required in order to grow itself.
The senses (for now there were several) became aware of a will - the will to live, specifically - simultaneously with a perception that some other entity was attempting to sequester its body - or part of its body. This was its first experience of something 'bad' - something it did not like. It liked the vibration and the undulation. It liked the movement. It did not like being eaten. So it retaliated. The assailant was half its size, so it simply oozed over, around and under it - and engulfed it. A new sense blossomed: a sense of satisfaction!
The senses now had a simple awareness and a will. The awareness informed the will. And the entity oozed about the mound in hunting mode. It didn't 'know' anything about cockroaches, except that they were present in great profusion and their tough little bodies contained a cocktail of chemicals suitable for building its own body. To start with, it pursued them, then it learned that it could grow itself more quickly by simply waiting for them to scurry over it. It spread itself quite thinly across an area of the mound, like a patch of sticky tar and trapped them.
These last few events came together as a sort of 'critical mass': an awareness, a will, a perception of the ability to move, the capacity to learn. From this point on, it grew apace. There was a great abundance of material - living creatures - in the heap that it could assimilate. Bacteria, mites, fungi, cockroaches, assassin bugs, baby bats, rats - all helped to build its body into something very large. There came a stage when it could almost have covered the mound, if it had spread itself thinly. It did do that briefly, but then it started to shrink (something it didn't like), because it was smothering the ecosystem that had grown and sustained it. It slithered to the base of the heap and pooled there, hungry, until the ecosystem recovered sufficiently for it to start growing again.
While it lay there, not hunting, not moving, conserving its energy, it started to think. It wondered. It formulated questions. It reasoned. It probed the dark recesses of its environment with delicate tendrils of thought. It grew a mind!
The populations living in and on the fuming heap of bat droppings that filled half the cave recovered and the entity recommenced hunting and feeding. This time, it split itself into separate portions that oozed independently over the heap and periodically reassembled with the main body to redistribute nutrients through the whole. Now the one mind had many bodies potentially, that split and merged at will. It seemed not to occupy any of them, so much as somehow hover outside them, receiving sense data from all. It's capacity to reason expanded.
Slowly, it perceived that it had found limits. Physical growth would be limited by its food supply, even if it farmed and herded the denizens of the mound. It considered the upper reaches of the cave from which the mound was constantly replenished by a rain of guano and baby bats. It sent forth its emissaries to search for further supplies. Oozing up the walls of the cave was more tricky than oozing over the mound of guano - but it learned the trick quickly. Hanging from the cave ceiling was a vast food supply.
Segments of the entity swarmed up the walls like moving oil slicks. The bats flew around in panic. The cave was a place of permanent mid-night. The first raid came when it was day time out in the world. There was only one exit, via a long, convoluted tunnel and out through a narrow opening. Most of the bats flew out to escape the marauding army of slime patches - into the daylight, where they flapped around in confusion, being picked off by predatory birds. The majority survived and most of those returned to the home cave.
It couldn't last. The entity hunted the cave ceiling relentlessly, day and night. At night, when the adult bats were abroad, it took the young from their crèches. During the day, it took the adults. By the time it had wiped out nearly all the bats, it was huge. This time it had really succeeded in destroying the ecosystem that sustained it. Without the bats to replenish the heap of guano, the bacteria and cockroaches stopped reproducing and the rats left.
The entity had become self-aware, it realised it was starving and it felt a new emotion: fear. All its parts drew in together for comfort and to share the remaining nutrients. It gradually shrank. Too late, it looked for a way out of the cave. Before it could find the way to the surface, it had shrivelled away entirely, never to trouble the creatures that live on the surface. We should all be grateful for that.