Aha you have stumbled across a phenomena known as the BLACK HOLE THREAD. They don't actually disappear though...oh no...nothing as simple. They whoosh into outer space at a speed immeasurable in human terms and there they stay.

Until, slowly slowly catch the monkey, they home in on each other. By developing the ability to emit high pitched beeping, only audible to other posts, they have discovered the ability to 're-group.' Still with me?

These highly sophisticated posts then form themselves into THREADS. They categorise and prioritise and wait...........

Light years from now these THREADS will form into FORUMS.

If their higher powers continue to evolve to a peak as yet unknown to man, we can only hope that from the eerie ether of blackness we will hear a soft wailing sound. At first just a solitary wail. But it will grow and strengthen.

These wails form into MODS.

Then the whole process goes tits up and we are left with a life form similar to a barnacle.