Physical Descriptions & Attributes
The Giant Insects are depicted as a pair of Extatosoma Tiaratum, native to Australia. They are unique insects that imitate leaves and branches to avoid being eaten by prey. Here in the Facility, they are of an abnormal size for unknown reasons, possibly a mutation or the insects have surpasses expected rate of growth, ignoring evolution.
Leaves and branches might be what summons them, but this is not confirmed.
The Giant Spiny Leaf Insects are in the sounding cameo apperance kong skull island. They can only be seen in the behind the scenes footage of the film.
They may have been inspired by various films about giant insects, or simply that their uniqueness makes them interesting if they actually were giant.