HELP. There are tiny red bugs in my cats food bowl? Please help.?

So 3 days ago we founds hundreds of little tiny red bugs in my cats dry food bowl and all around the food bowl, we wiped them up and just thought they were little bugs infesting the house. For some reason we didn't put two and two together. Then the next day we feed him, no bugs and the food was on the table. Then I wake up today. I go to feed him (the food bowl was now on the floor) and little bugs are everywhere and my cat vomited his food up today. What are these bugs? They are way too small to be ants, they look like red nats and they don't fly. I know we should buy a new bag of food in case, but I want to know what they are and where they come from?