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 11 entrance guard DHJanzen101026.jpg high resolution
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| In the face of the road bank, the bee digs a tunnel back in for a few inches and excavates small cells that it fills with pollen and some nectar. It lays an egg in the cell and then seals it. The bee larva eats the pollen and nectar in its cell, pupates, ecloses and digs its way out, to continue the cycle. Here, a bee guards the nest entrance against parasites and predators. However, to forage it must leave, and there is obvious selection favoring, for example, offspring to stay within the nest, guarding it, while another bee forages for food - leading down the slippery slope to social bees. Note that the algae are growing well in a patch around the entrance - fertilized by the waste materials from the bee nest. Also note the apron of freshly excavated dirt below the nest, pushed out by the bee as it excavated yet another cell deep in the soil. | ||
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