They have large heads, short tails, and powerful bills and feet. Nuthatches advertise their territory with loud, simple songs. Most species have grey or bluish upperparts and a black eye stripe.
Nuthatches use holes in trees for nests. This means they compete with squirrels and woodpeckers for these holes. In fact both squirrels and the great spotted woodpecker kill nuthatches if they can. Owls and hawks also kill these small birds, but that is not to do with their nest-holes. In defence of their nests, nuthatches make the entrances smaller by packing the edges with mud or tree resin. Predation is not really a threat, just a fact of life for them. Loss of coniferous forest in some countries is a threat. They cannot live except in trees.
All nuthatches store food, especially seeds. They hide seeds in tree crevices, in the ground, under small stones, or behind bark flakes. These stores are remembered for as long as 30 days.
- Harrap, Simon & Quinn, David 1996. Tits, nuthatches and treecreepers. Christopher Helm. ISBN 978-0-7136-3964-3
- Hardling, Roger; Kallander, Hans; Nilsson, Jan-Åke (1997). "Memory for hoarded food: an aviary study of the European Nuthatch" (PDF). The Condor. 99 (2): 526–529. doi:10.2307/1369961. JSTOR 1369961.