We present initial results from a project designed to monitor Ultracool Dwarfs (UCDs) of late-M to early-L spectral type in the near infrared (NIR) to evaluate the feasibility of detecting close- in, planetary companions to small stars. Owing to the small radii of the UCDs, data obtained with the Peters Automated Infrared Imaging Telescope (PAIRITEL) should allow us to detect terrestrial-size transiting planets. A sample of 20 objects was monitored nightly over a period of four months with a typical precision of ≈1%. To date, more than 106̂ seconds of observations have been collected. We find that UCDs represent photometrically stable targets suitable for transiting planet searches in the NIR. We present data from two targets with representative time coverage and photometric behavior. The likelihood of detecting an existing close-in planet in the PAIRITEL data using this observational strategy is simulated. We demonstrate that with effective integrations of 20 minutes we achieve 8 mmag rms over a period of 100 days, suggesting sensitivity to Earth size planets. A campaign to monitor a large sample of UCDs provides a viable method for detecting terrestrial planets, super-Earths, and Neptunes potentially located in the habitable zones of their hosts.