Abstract: Barrier devices against pest invasion are provided that allow sealing around a utility penetration (8), for example a pipe or conduit. In one embodiment, the barrier device is a barrier boot (2) that is sealed to a foundation slab (50), in order to prevent pest invasion through the spaces (52) formed between the foundation slab (50) and the utility penetration (8). In another embodiment, the device forms a continuous barrier with a surface receiving the utility penetration, for example a sheet-type barrier, a building foundation, footer or wall. In yet another embodiment, the device is a stand alone product which provides protection when embedded in concrete.