Abstract: An assembly for preventing pidgeons for entering the space between a pair of adjacent I-beams of a bridge or similar structure. In one embodiment, the assembly comprises a pair of generally C-shaped plastic clips and a generally rectangular plastic sheet. The clips are adapted to be mounted around the bottom surface and the lower inner and lower outer flanges of the I-beam. The plastic sheet is dimensioned so as to extend across the space between the pair of adjacent I-beams and to rest on top of the inner flanges of the I-beams. A plurality of small openings are formed in the plastic sheet. The pair of generally C-shaped clips are inserted through a pair of respective openings located on opposite sides of the plastic sheet.