I don't eat at the laptop so I don't see how the food could've got there.
Ants will actually feel up the electrical components in a computer, as their antennae come into contact with the parts conducting electricity, it stimulates their brain similar to the way sugar does and causes them to release pheromones that attract other ants. This is a major problem in some airports as the ants will completely infest air-traffic control tower terminals and cause shorts or connection cuts from when they chew through the wiring.
