To try to analyze what kind of insect becomes Gregor it is necessary to highlight, in The Metamorphosis does not say that it is an insect, bug, beetle or cockroach.
The story is not clear in the species but specific in its associations: it is always a kind of small and multiple paw, of an expansive, insatiable and promiscuous nature, a being so repulsive that it produces chills just by being mentioned.
Kafka never explains it.
One of the broadest interpretations points to Gregorio Samsa becoming a cockroach. However, a closer analysis indicates that we are facing another type of creature.
Nabokov analyzed the clues given by Kafka to draw his conclusions about the shape and size of the insect. And he comes to determine that it looks like a cockroach in only one aspect: its color is brown.
For Nabokov, there are other evident proofs to think that it is actually a beetle: the "strong jaws" of Gregory, the "huge convex belly divided into segments" or his "hard round back" are some examples.
According to some sources, it seems indisputable that Kafka intentionally chooses the words so as not to make clear what kind of insect Gregorio Samsa is,
Nabokov stating book sentences: "Gregorio the beetle never realizes that it has wings under the hard covering of its back". That is to say, that the actor of the most anguished story in universal literature is really a creature that can fly and escape from the place without knowing it like so many of us.
