system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why do spiders not bleed out and die when losing a limb?

As a human if I lost a limb I would most likely bleed out and die within minutes if I didn't get medical attention but spiders are like "Oh no... Anyway..." And they just keep on trucking. Why is that?
gpt
Because arthropods don’t necessarily use blood to circulate oxygen throughout their bodies.  In ELI5 terms, they instead have small holes through their bodies for oxygen to enter directly and spread locally.