The investigation of the local polarization switching including direct domain writing, local hysteresis measurements, and domain stability testing was carried out in single-crystalline stoichiometric lithium tantalate using the Scanning Probe Microscope. Piezoresponse Force Microscopy was utilized for domain visualization and recording of local switching characteristics. Two variants of domain patterning were shown: direct writing and self-assembled formation. The polarization reversal in direction opposite to applied field (anti-parallel switching) was studied in details and attributed to screening of external field.