 Davidson appears to be employing a very high standard for attributing concepts to animals. In effect, he is asking for proof that our attributions are correct. In contrast, most philosophers who are happy to attribute concepts to animals do so because of a wealth of data that are best explained by appealing to an internal system of representation (e.g., Bermudez 2003, Carruthers 2006, Camp 2009; for overviews within cognitive science, see Gallistel 1990, Bekoff, Allen, &amp; Burghardt 2002, and Shettleworth 2010). For example, many species of birds cache food for later retrieval. Their very survival depends upon their ability to successfully recover, in some cases, more than 10,000 different caches in a single season. Researchers studying one species of caching birds have shown that not only do the birds represent the location of the food, but they integrate this information with information about the quality of the food, its perishability, and whether their caching was observed by other birds. Evidence here comes from demonstrations of selective retrieval and recaching of food items under experimentally controlled conditions. Birds will retrieve more perishable items first. When highly valued food items become highly perishable, they shift strategies to retrieve a higher percentage of less perishable food items. And birds that have themselves stolen food from other birds will selectively recache stored food when they are observed caching it (see Clayton, Bussey, &amp; Dickinson 2003, Emery, Dally, &amp; Clayton 2004). Experimental data of this kind provide evidence for particular concepts in birds (of food types, locations, and so on) as well as surprisingly sophisticated cognitive operations that make use of them.