Humans: *dramatic panic* "SOUND THE ALARMS! DEPLOY ALL IMMUNE CELLS! WE'RE UNDER ATTACK!"
Horseshoe crabs: "Blood infection? Cool, I'll just solidify my entire bloodstream. Problem solved."
This meme is pure evolutionary flex! Horseshoe crabs have survived 450 MILLION years with their simple yet effective immune strategy. Their blue copper-based blood contains amebocytes that instantly clot when they detect bacterial endotoxins - so sensitive we literally use their blood (LAL assay) to test medical equipment for contamination. Meanwhile, our complex immune system is having a full-on meltdown over every little pathogen. Sometimes simpler IS better!