Arthropods have an open blood circulatory system, therefore Periplaneta also has an open circulatory system. Octopus belongs to order Sepia.

And like vertebrates, earthworms have a brain that produces hormones in times of stress. Then there’s the closed circulatory system, complete with arteries, veins and capillaries. The earthworm’s blood contains hemoglobin, the red protein that carries oxygen, just as in our blood.

As opposed to a closed system, arthropods– including insects, crustaceans, and most mollusks– have an ‘open’ circulatory system.

It lives in contaminated soil, so it only enters the body when people ingest the eggs. Inside the body, this worm lives in the intestines. People with an ascariasis infection often show few to no symptoms. However, severe infections may cause intestinal blockages or impair growth in children.

Accidentally ingesting maggots does not generally cause any lasting harm. However, if a person has ingested maggots through eating spoiled food, they may be at risk of food poisoning. Symptoms of food poisoning can range from very mild to serious, and they can sometimes last for several days.

If an earthworm is split in two, it will not become two new worms. The head of the worm may survive and regenerate its tail if the animal is cut behind the clitellum. But the original tail of the worm will not be able to grow a new head (or the rest of its vital organs), and will instead die.

Most people find that holding a worm is fun and ticklish. You should not be afraid to hold a worm.

Keeping Worms Happy

1. Worms need to live in a warm, dark place. Red wigglers like the temperature to be between 40-75 degrees.
2. Worms need moisture in their environment. The texture of their bedding should feel like a wrung-out sponge.
3. Worms need air. Worms breathe through their skin!
4. Worms need food!
5. Worms need to wiggle!