In his youth he had a noted talent for drawing, and in 1908 he entered the Ipswich School of Art, studying under George Rushton.
[1][2] In 1920 Squirrell went to the Slade School of Fine Art, where he studied under Henry Tonks and Philip Wilson Steer.
From 1929 he taught etching at the Ipswich School of Art, succeeding Charles Edward Baskett, and remained there until 1940.
He produced railway posters, and images for many commercial companies, such as Ransomes Sims and Jefferies and Fisons.
Their son Martin Squirrell (1926–1950) had three works exhibited at the Royal Academy in 1943, and became art editor of the East Anglian Magazine.