Marie Read / Eastern bluebird (Sialia sialis) male fluttering wings while perched on cherry (Prunus sp.) branch in spring, New York, USA, April.

Lynn M. Stone / Shetland sheepdog running in Common bluet (Houstonia caerulea) field. Haddam, Connecticut, USA. May.

Lynn M. Stone / Shetland sheepdog standing in Common bluet (Houstonia caerulea) field. Haddam, Connecticut, USA. May.

Lynn M. Stone / Chocolate labrador retriever, adult and puppy in Common bluet (Houstonia caerulea) field. Haddam, Connecticut, USA. May.

Lynn M. Stone / Chocolate labrador retriever, two puppies lying in Common bluet (Houstonia caerulea) field. Haddam, Connecticut, USA. May.

Lynn M. Stone / Chocolate labrador retriever puppy lying in Common bluet (Houstonia caerulea) field. Haddam, Connecticut, USA. May.

Ross Hoddinott / Holly blue butterfly (Celastrina argiolus) resting on Ivy (Hedera sp), Broxwater, Cornwall, UK. April.

Jussi Murtosaari / Holly blue butterfly (Celastrina argiolus), female, Finland, June.

Bernard Castelein / Holly blue butterfly (Celastrina argiolus) Brasschaat, Belgium

Bernard Castelein / Holly blue butterfly (Celastrina argiolus) Brasschaat, Belgium

Sue Daly / Holly blue butterfly (Celastrina argiolus) on heather, Sark, British Channel Islands, August.

Sue Daly / Holly blue butterfly (Celastrina argiolus), Sark, British Channel Islands, August.