Bogs produce a potent greenhouse gas called methane. This gas is produced in the sediments of a bog by microbes called archaea. Some bacteria use methane as an energy source, but do not consume all of it before it reaches the surface. You may recognize methane as the major component of natural gas, which is of course flammable.
Alessandro Volta performed an experiment in 1776 where he showed that gas from disturbed decaying plant matter could start on fire. Much later, it was discovered that this methane was produced by microbes. Today scientists perform the Volta Experiment with a large funnel. Below is a demonstration video from Rutgers – just remember, don’t try this at home! (But if you think this looks like fun, maybe you should consider a career in science!)