[4] In addition to entomology, he collected ivory work, weapons, and first editions of illustrated books.
It is said that what would have usually been a short audience lasted for two hours, while the emperor and Natvig eagerly leafed through the publications.
He was described "as a good lecturer and speaker who popularized and could act out the behavior of insects when he talked about them, he had ... a gracious nature and was helpful and easy to connect with.
[5] Natvig worked deliberately, and it was not until 1937 that he produced an elaborate thesis, almost a full volume, on warble flies in Scandinavia.
Natvig himself collected a great deal of material during his travels in southern Norway, which encompassed over eighteen summers.
Natvig's examiner at his doctoral defense, Hjalmar Broch, is said to have stated "this is apparently evidence that a mosquito can turn into an elephant.
Natvig also had a large amount of material on Anopheles mosquitoes, and he did some work on this genus of insects.
That same year he was elected a deputy member of the board, and he performed many duties and was very active in the society.
[5] Natvig published several major works and a number of shorter articles on his field of study, including several obituaries of entomologists.