Boring insects make interesting music.

This article cites a study, conducted by Noam Amir of Tel Aviv University in Israel who analyzed eight didgeridoos and found that the randomness of the bores had a unique effect on the sound they produced. Traditionally, didgeridoos are made from eucalyptus branches that have been hollowed out by termites, and so have randomly shaped bores. Wind instruments normally resonate at the fundamental frequency at which they are played and also at the fundamental's higher harmonics. Amir also found that players are able to manipulate their vocal tracts to produce resonances that coincide with the ninth and higher harmonics of the fundamental frequency.