John Chan / Honey bees (Apis mellifera) gathering at the entrance of their nest in a hollow log, with some returning workers carrying pollen baskets, Bolsa Chica Ecological Reserve, California, USA, October.

Michael Durham / Honey Bee (Apis mellifera) with pollen baskets, Oregon

Ammonite / Buff-tailed bumble bee (Bombus terrestris) removing pollen baskets from back legs into a wax honey pot in nest, France, May.

Michael Durham / Honey Bee (Apis mellifera) with pollen baskets taking flight from garden flower

Michael Durham / Honey Bee (Apis mellifera) worker collecting nectar from Red Clover (Trifolium pratense) flowers, note the pollen baskets on the legs, northwest Oregon

Konrad Wothe / Honey Bee (Apis mellifera) collecting pollen from willow flower, note full pollen baskets, Germany

Konrad Wothe / Honey Bee (Apis mellifera) collecting pollen from daisy, note pollen baskets on hind legs, Germany

Phil Savoie / Buff tailed bumblebee (Bombus terrestris) queen flying to Oriental poppy flower (Papaver orientale) with pollen baskets, Monmouthshire, Wales, UK. July.

Phil Savoie / Yellow legged mining bee (Andrena flavipes) female with full pollen baskets, on bank of the River Monnow, Monmouthshire, Wales, UK. April

Phil Savoie / Yellow legged mining bee (Andrena flavipes) female with pollen baskets full, outside nest burrow, Monmouthshire, Wales, UK. September

Phil Savoie / Orange legged furrow bee (Halictus rubicundus) feeding on Poached egg flower (Limnanthes douglasii), showing pollen baskets on hind legs, Monmouthshire, Wales, UK. March.

Heather Angel / Honey bee (Apis mellifera) with full pollen baskets feeding on Balkan anemone (Anemone blanda). In garden. Surrey, England, UK. April.

Heather Angel / Honeybee (Apis mellifera) with full pollen baskets and pollen on head, thorax and abdomen. Bee withdrawing from Snowdrop (Galanthus nivalis) flower after nectaring. In garden, Surrey, England, UK. Feb...

John Chan / Honey bees (Apis mellifera) gathering at the entrance of their nest in a hollowed log, with some returning workers carrying pollen baskets, Bolsa Chica Ecological Reserve, California, USA, October.

Phil Savoie / European honey bee (Apis mellifera) with full pollen baskets, feeding on Cherry tree (Prunus sp.) Monmouthshire, Wales, UK, March.

Ammonite / Ashy mining bee (Andrena cineraria) with full pollen baskets / sacs, Bristol, England, UK, May.

Michael Durham / Bumblebee (Bombus sp) flying with large pollen baskets, Cherokee National Forest, Tennessee

Chris Gomersall / 2020VISION / Buff-tailed bumble bee (Bombus terrestris) on Field poppy (Papaver rhoeas) showing fully laden pollen baskets, RSPB Hope Farm, Cambridgeshire, UK, May

Scott Leslie / Honey Bee (Apis mellifera) gathering pollen with pollen baskets on legs, Annapolis Valley, Nova Scotia, Canada

Heidi & Hans-Juergen Koch / Honey Bee (Apis mellifera) with pollen baskets on hind legs, Bee Station at the Bavarian Julius-Maximilians-University of Wurzburg, Germany

Michael Durham / Honey Bee (Apis mellifera) with pollen baskets on garden flower

Heidi & Hans-Juergen Koch / Honey Bee (Apis mellifera) with pollen baskets, Bee Station at the Bavarian Julius-Maximilians-University of Wurzburg, Germany

PREMAPHOTOS / Honey / hive bee worker (Apis mellifera) with its pollen baskets full of pollen from the fleabane on which it is foraging, UK

Michael Durham / Bumblebee (Bombus huntii) with full pollen baskets, flies from a Rhododendron flower, northeast Oregon

Michael Durham / Honey Bee (Apis mellifera) with pollen baskets approaching English Lavender (Lavandula angustifolia) flowers, western Oregon

Michael Durham / Honey Bee (Apis mellifera) flying away from English Lavender (Lavandula angustifolia) flowers with pollen baskets, western Oregon

Michael Durham / Honey Bee (Apis mellifera) flying away from English Lavender (Lavandula angustifolia) flowers with pollen baskets, western Oregon

Michael Durham / Honey Bee (Apis mellifera) with pollen baskets taking flight from garden flower

Mark Moffett / Honey Bee (Apis mellifera) collecting nectar from the flowers of a wild Cinnamon tree (Neolitsea cassia) note full pollen baskets, Sinharaja Forest Reserve, Sri Lanka

Nick Upton / Red-tailed bumblebee (Bombus lapidarius) worker with fully laden pollen baskets entering nest burrow in mature, stable sand dunes, Kenfig National Nature Reserve, Glamorgan, Wales, UK. June.

Nick Upton / Tree bumblebees (Bombus hypnorum) at entrance to bird nest box they have taken over on house wall, with one returning with fully loaded pollen baskets, Wiltshire, UK. June.

Brian Bevan / Tree bumblebee (Bombus hypnorum) two returning to nest with full pollen baskets, Bedfordshire, UK, May.

Brian Bevan / Tree bumblebee (Bombus hypnorum) returning to nest with full pollen baskets, Bedfordshire, UK, May.

John Chan / Honey bee (Apis mellifera) foragers returning to their hive, some with pollen baskets, while guard bees clean the hive entrance. Bolsa Chica Ecological Reserve, Southern California, USA, September.

John Chan / Honey bee (Apis mellifera) foragers returning to their hive, some with pollen baskets, while guard bees clean the hive entrance. Bolsa Chica Ecological Reserve, Southern California, USA, September.

Phil Savoie / Early bumblebee (Bombus partorum), visiting Green alkanet (Pentaglottis sempervirens) native pollinator, worker bee with full pollen baskets, Monmouthshire, Wales, UK, June

Phil Savoie / Buff-Tailed bumblebee worker (Bombus terrestris), feeding on Clover (Trifolium sp.) with full pollen baskets, Monmouthshire, Wales, UK

Nick Upton / Chocolate mining bee (Andrena scotica) female with full pollen baskets basking on leaf. Wiltshire, England, UK. April.

Nick Upton / Common furrow bee / Slender mining bee (Lasioglossum calceatum) with full pollen baskets approaching her nest burrow in an arable field margin, Wiltshire, UK, April.

Nick Upton / Common furrow bee / Slender mining bee (Lasioglossum calceatum) with full pollen baskets entering her nest burrow in an arable field margin, Wiltshire, UK, April.

Nick Upton / Chocolate mining bee (Andrena scotica) female flying down to her nest burrow with loaded pollen baskets to provision her brood cells, Wiltshire garden, UK, April.