Assassin bugs are predatory insects found worldwide with around 7,000 species, 50 in California. They're known as "kissing bugs" for biting near the mouth.
Crocodiles are semiaquatic reptiles found in tropical regions across the world. Most subspecies have similar traits and behavior.
Scorpions are arachnids from the Scorpiones order, existing for 435 million years. They control pests and have eight legs, segmented tails, claws, and a stinger on their back.
Ascaris lumbriocoides is a parasitic roundworm that causes ascariasis, common in tropical regions. About one-sixth of humans are infected with some form of roundworm.
Mosquitoes are small insects from the Culicidae family with over 3,500 species found worldwide (except Antarctica).
They feed on the blood of vertebrate animals and are known to spread diseases that can infect humans and livestock, causing an economic burden in sub-Saharan Africa.
Nearly 4,000 species exist and they are filter feeders or detritivores, found in various habitats such as rivers, lakes, and ponds.
Over 3,000 species exist worldwide, ranging in size from tiny to large. Snakes originated from lizards, and many may have had legs in the past. They are fascinating but also dangerous, causing human deaths annually.