You don’t have to go far to find some of the deadliest species around.

Whether we want to acknowledge it or not, they walk among us. Some insects and animals might be right outside your home. The key to handling critters is simple: “don’t bug them, and they won’t bug you!” Some dangerous species, like the hybrid “killer bee,” were created by humans. Even dogs, often called man’s best friend, can pose risks if unvaccinated. Here’s a list of the world’s most dangerous species to recognize and know how to stay safe.

The Blue-Ringed Octopus is considered one of the most venomous marine animals in the world, especially if they feel threatened (they are usually passive).

If a blue-ringed octopus does feel threatened, it can sting with toxins powerful enough to result in death. The venom causes paralysis of the respiratory muscles, so if a person is stung, artificial respiration is needed. They can be found in coral reefs and tide pools in the Indian and Pacific Oceans.