I guess

if there is dark matter and if it is made up of particles - these
particles could scatter using gravity - they would not scatter like 2
rubber balls

electron, protons, neutrons and dirt going through these particles
would be a lot like neutrinos going through the earth - if that was not
true - electrons, protons, neutrons and dirt would be bouncing off dark
matter - dark matter would be flying all over the universe

it is probably true these particles would have an extreme small amount
of mass because if they had a lot of mass they would scatter like
electrons, protons, neutrons and rubber balls

Kurt Stocklmeir