Nectar robbing is a foraging behavior used by some organisms that feed on floral nectar, carried out by feeding from holes bitten in flowers, rather than by entering through the flowers' natural openings. Nectar robbers usually feed in this way, avoiding contact with the floral reproductive structures, and therefore do not facilitate plant reproduction via pollination. Because many species that act as pollinators also act as nectar robbers, nectar robbing is considered to be a form of exploitation of plant-pollinator mutualism. While there is variation in the dependency on nectar for robber species, most species rob facultatively.
Bombus terrestris stealing nectar
Biting open the base of a flower...
...and using its tongue to drink the nectar.
Carpenter bees are species in the genus Xylocopa of the subfamily Xylocopinae. The genus includes some 500 bees in 31 subgenera. The common name "carpenter bee" derives from their nesting behavior; nearly all species burrow into hard plant material such as dead wood or bamboo. The main exceptions are species in the subgenus Proxylocopa, which dig nesting tunnels in suitable soil.
Carpenter bee
Xylocopa caerulea, the blue carpenter bee, engaged in nectar robbing
Xylocopa virginica in the United States
Cross-section of the brood chambers of X. violacea, illustrated by Theo Carreras. Tunnels are excavated in wooden posts, divided into chambers which are provisioned, and an egg is laid in each. Each cell initially contains a mass of pollen with the egg, on which the grub will feed. The pupa (lower left) is seen from back and front.