Introduction and purpose:
Venoms and poisons are chemical weapons in the animal world. Venomous and poisonous invertebrates produce poisons for defensive purposes or in order to obtain food. These animals have developed morphological and physiological adaptations (venom organs and glands), which enable the penetration of venom or poison into or onto the body of other animals or humans. In humans, these substances cause organ disorders, allergic and toxic reactions, sometimes even leading to death. Knowledge of the places of habitation and ways of behaviour of these animals may protect an individual against the loss of health or even life. The objective of the study is the presentation of selected species of poisonous and venomous animals belonging to invertebrates, which are dangerous for human health and life.

Description of the state of knowledge.:
The article presents the species most dangerous for humans, the venom of which is lethal. Venomous invertebrates include: Cnidaria, scorpions, spiders, shellfish (snails, cephalopods), e.g. scyphozoans of the Chironex species, caracurt (Latrodectus mactans tredecimguttatus). The poisonous invertebrates include some butterflies (monarch butterfly – Danaus plexippus) and beetles (Spanish fly – Lytta vesicatoria).

Summary:
Knowledge concerning venomous and poisonous animals is very useful for people who travel to tropical countries. Unfortunately, this knowledge is still insufficient, both among tourists and employees of travel agencies.