Following KC Tsang’s observation of a woodpecker checking out a hole in a concrete pole, Ragoo Rao of India wrote: “Yes, I agree, the woodpeckers do explore for insects in concrete pole holes also. I have photographed Black-rumped Falamebacks (Dinopium benghalense), doing this.
“I have noticed the woodpecxkers cling on to electric poles to explore for insects in the holes. This they do only when there are holes in the pole and not otherwise. I have observed this for a long time and in all occasions the woodpeckers landed only on concrete poles with holes, which might appear to them as tree trunk holes, to get insects.”