Sven Zacek / Trees that have been gnawed by Beavers (Castor fiber) Southern Estonia, October.

Sven Zacek / Black woodpecker (Dryocopus martius) male excavating nest hole in Aspen (Populus tremula) trunk. Tartumaa, Southern Estonia. April. Composite image.

Marie Read / Male Downy woodpecker (Picoides pubescens) excavating nest cavity, tossing wood chips out of nest hole in tree trunk, Lansing, New York, USA, May.

Mark Hamblin / 2020VISION / Sign for biomass heating using wood chips to generate heat. Scotland, UK, May.

Mark Hamblin / 2020VISION / Information sign about biomass heating using wood chips. Scotland, UK, May.

Mark Hamblin / 2020VISION / Wood chips in store, used as fuel, Alvie estate, Scotland, UK, May..

Mark Hamblin / 2020VISION / Sign for HWE biomass heating company using wood chips to generate heating. Scotland, UK, May.

Mark Hamblin / 2020VISION / Delivery of wood chips for use by local hotel to supply heating, Kingussie, Scotland, UK, May.

Adrian Davies / Hare's Foot Inkcap (Coprinus lagopus) close-up showing upturned gills. Growing on wood chips. Surrey, England, UK, September

Adrian Davies / Bleach cup fungus (Disciotis venosa) growing on wood chips in woodland. Surrey, England.

Jerry Monkman / Wood chips created by American beaver {Castor canadensis} Goshen, Connecticut, USA

Nigel Bean / Toadstools {Stropharia aurantiaca} growing in wood chips, Somerset, UK.

Bernard Castelein / Black woodpecker (Dryocopus martius) feeding with wood chips flying, on tree trunk. Peerdsbos, Brasschaat, Belgium. May.

Jussi Murtosaari / White-backed woodpecker (Dendrocopos leucotos), female excavating nest in birch tree, expelling wood chips from hole, Finland, April.