Shot-noise contributions to auto-spectra of the various fields measured from the AGN BAHAMAS simulation. We show the ratio of the shot-noise to the auto-spectra as a function of scale for matter (purple), CDM (green), gas (blue), stars (orange) and electron pressure (yellow). The dashed line shows the cutoff for a one percent contribution. We see that shot noise is most important for the gas power spectrum at higher redshifts, where it can contribute as much as 8% of the raw measured power for the smallest scales shown. Generally shot noise becomes less important as the simulation evolves and structure develops.