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We report the white light flare rates for 10 ultracool dwarfs (UCDs) using\textit{Kepler K2} short cadence data. Among our sample stars, two havespectral type M6, three are M7, three are M8 and two are L0. Most of ourtargets are old low mass stars. We identify a total of 283 flares in all of thestars in our sample, with \textit{Kepler} energies in the range log\textit{E$_{Kp}$} $\sim$(29 - 33.5) erg. Using the maximum-likelihood method ofline fitting, we find that the flare frequency distribution (FFD) for each starin our sample follows a power law with slope -$\alpha$ in range -(1.3-2.0). Wefind that cooler objects tend to have shallower slopes. For some of ourtargets, the FFD follows either a broken power law, or a power law with anexponential cutoff. For the L0 dwarf 2MASS J12321827-0951502, we find a veryshallow slope (-$\alpha$ $=$ -1.3) in the \textit{Kepler} energy range(0.82-130)$\times$10$^{30}$ erg: this L0 dwarf has flare rates which arecomparable to the rates of high energy flares in stars of earlier spectraltypes. In addition, we report photometry of two superflares: one on the L0dwarf 2MASS J12321827-0951502 and another on the M7 dwarf 2MASSJ08352366+1029318. In case of 2MASS J12321827-0951502, we report a flarebrightening by a factor of $\sim$144 relative to the quiescent photosphericlevel. Likewise, for 2MASS J08352366+1029318, we report a flare brightening bya factor of $\sim$60 relative to the quiescent photospheric level. These twosuperflares have bolometric (UV/optical/infrared) energies 3.6 $\times$10$^{33}$ erg and 8.9 $\times$ 10$^{33}$ erg respectively, while the FWHM timescales are very short, $\sim$2 minutes. We find that the M8 star TRAPPIST-1 ismore active than the M8.5 dwarf: 2M03264453+1919309, but less active thananother M8 dwarf (2M12215066-0843197).

K2 Ultracool Dwarfs Survey. III. White Light Flares are Ubiquitous in M6-L0 Dwarfs