  Galaxy number counts probe the evolution of galaxies over cosmic time, and
serve as a valuable comparison point to theoretical models of galaxy formation.
We present new galaxy number counts in eight photometric bands between 5 and 25
$\mu$m from the Systematic Mid-infrared Instrument Legacy Extragalactic Survey
(SMILES) and the JWST Advanced Deep Extragalactic Survey (JADES) deep MIRI
parallel, extending to unprecedented depth. By combining our new MIRI counts
with existing data from Spitzer and AKARI, we achieve counts across 3-5 orders
of magnitude in flux in all MIRI bands. Our counts diverge from predictions
from recent semi-analytical models of galaxy formation, likely owing to their
treatment of mid-infrared aromatic features. Finally, we integrate our combined
JWST-Spitzer counts at 8 and 24 $\mu$m to measure the cosmic infrared
background (CIB) light at these wavelengths; our measured CIB fluxes are
consistent with those from previous mid-infrared surveys, but larger than
predicted by some models based on TeV blazar data.
