The text is about an insect called : The emerald cockroach wasp. This Wasp stings her host animals, normally cockroaches, to make them follow her into her lair to lay her eggs into the body of the host.
The author gives human characteristics to the parasites and their animal host to validate his idea of the Zombie concept he coined to refer to the wasp.
By seeding the idea that if a wasp can make zombies with a cocktail of venom, the author also raises the doubt that it might be possible to extrapolate that kind of control to humans.