Paintballs are trickier than just a water balloon. They have to be rigid/strong enough to survive the blast of co2 or compressed air that propels them, then they have to be soft enough to break on impact without harming the other player.

They also just aren’t that messy. I worked under the table as a referee at a Paintball place when I was 13, and we played such that gameplay didn’t stop when refs were doing paint checks. We’d toss people out if they were intentionally focusing on us but I got lit up probably 10+ times a day, every weekend for 2 years. My jersey and slider pants came clean in the wash every time, and to this day the only lasting blemishes are the shredded fabric on the knees/elbows/ass from when I dove and slid a lot.

Man, corvids are so cool. My life goals include becoming friends with a murder of crows. I came close one time while training a pup to walk with training treats; she was super messy and dropped them all the time, and the crows started to recognize whenever we were walking and follow us to get those fallen treats. Unfortunately the pup loved to bark her head off and chase them around, and they did not like that. They even tried to drive me off once or twice by feinting diving attacks at my head

Kilroy was here

Fun fact; the standard model actually allows for spontaneous particle-antiparticle pair generation, so long as the pair mutually annihilate within some hbar defined time limit and conservation laws aren’t broken at a macro scale. This is the mechanism behind hawking radiation too; some of the energy given off by black holes is caused by spontaneous pair generation that happens such that one of the pair is created beyond the event horizon and the other member is created before the event horizon, causing one to be trapped and the other to be jettisoned into space.

I know that doesn’t really relate to your comment about containing antimatter but I counter with the following: I’m profoundly autistic and the standard model has been a special interest of mine before. I couldn’t resist the chance to infodump a bit