We have the main power to the coop via buried cable fed by GFCI circuit. Once in the coop, we distribute the power via 3 wire commercial quality extension cord securely fastened to the ridge pole of our "gabled hoop house" type coops. We then use triple taps for heat lamps, stock tank heater (winter), heat tapes, fans, lights, etc. As long as there are no dangling wires, the chickens don't pay any attention to them. But if the plug of an idle heat lamp is hanging, they will leap at it to pull it.
Where they can reach the cord from the roost, once they examined it (by pecking, of course), and found it presented no food value, they very quickly lost interest. The occasional rodent, especially chipmunks, don't lose interest as easily so keeping wiring high and secure helps.
Be sure your circuits are protected by GFCI and circuit breaker. If we had a wooden frame building, we'd have wired it conventionally with armored cable and metal boxes.