Spending most of her career at Bergen Museum, from 1949 to 1979, she was the first female member of the Norwegian Entomological Society, and specialized in the bumblebee genus Bombus.
In the spring of 1941, Løken was recruited to XU, a clandestine intelligence organization which answered to the Norwegian High Command-in-exile in the United Kingdom.
Under the cover of studying the genus Bombus, she had been cleared by Reichskommissar Josef Terboven, the highest Nazi leader in Norway.
Travelling freely in the area, Løken managed to photograph roads, bridges and other installments.
[4] She described the Department of Entomology at Michigan State College as "impressing", in contrast to the "miserable" conditions in Norway at the time.
[5] However, in Michigan, the unmarried Løken was barred from conducting field research together with married men, as this could "spoil their reputation".
[6] She returned to Norway, and was given her first academic position as a research assistant at the Norwegian College of Agriculture.