  Using a sample of 361 nearby brown dwarfs, we have searched for 4.6$\mu$m
variability indicative of large-scale rotational modulations or large-scale
long-term changes on timescales of over 10 years. Our findings show no
statistically significant variability in \textit{Spitzer} ch2 or \textit{WISE}
W2 photometry. For \textit{Spitzer} the ch2 1$\sigma$ limits are $\sim$8 mmag
for objects at 11.5 mag and $\sim$22 mmag for objects at 16 mag. This
corresponds to no variability above 4.5$\%$ at 11.5 mag and 12.5$\%$ at 16 mag.
We conclude that highly variable brown dwarfs, at least two previously
published examples of which have been shown to have 4.6$\mu$m variability above
80 mmag, are very rare. While analyzing the data, we also developed a new
technique for identifying brown dwarfs binary candidates in \textit{Spitzer}
data. We find that known binaries have IRAC ch2 PRF (point response function)
flux measurements that are consistently dimmer than aperture flux measurements.
We have identified 59 objects that exhibit such PRF versus apertures flux
differences and are thus excellent binary brown dwarf candidates.
