Indirect evidence of ‘dark photons’ has been spotted in the shrapnel of thousands of particle-smashing experiments. This could provide a glimpse into the mysterious nature of dark matter — which seems to make up most of the mass of the universe but is almost impossible to observe, other than by its gravitational effects. “The story is something like this: there could be an additional dark sector, where dark matter resides,” says particle physicist Carlos Wagner. Dark photons, if they exist, could weakly interact with normal matter, offering a window into the dark sector.
Based on what we know, dark matter doesn’t seem to collide with anything - not even itself. If we are correct (and if I am not mistaken), there doesn’t seem to be enough complexity in its dynamics to support life.
In what way does dark matter interact with matter/light that people think it exists, is it gravitational?
Yes, DM interacts gravitationally with itself and normal particles.