6.4.1. Natural honey bee light conditions
Honey bees typically spend a considerable amount of their lives in mostly dark conditions within the hive, although late in life, light-dark cycles play a crucial role in determining foraging rhythm of workers (Moore, 2001). An exception includes some Apis mellifera adansonii that may nest in the open (Fletcher, 1978). Despite phototaxis (i.e. movement toward or away from a light stimulus) varying relative to bee age, light intensity, and light wavelength (Menzel and Greggers, 1985; Ben-Shahari et al., 2003; Erber et al., 2006), permanent exposure to honey bee-visible light can affect hoarding behaviour (i.e. the collection and storage of food in the honey stomach) of caged honey bees (Free and Williams, 1972). To our knowledge, honey bees in the laboratory are always maintained in complete darkness (e.g. Malone and Stefanovic, 1999; Maistrello et al., 2008; Alaux et al., 2009); however, many studies fail to report light conditions.