Goosebumps are tiny bumps on your skin caused by muscle contractions around hair follicles. These contractions occur when the body is cold or experiencing strong emotions like fear or excitement. They are a vestigial reflex to fluff up fur for insulation or appear larger to predators.
This fact belongs to the general category and contributes to expanding general knowledge. Understanding such facts not only makes you smarter but also helps connect ideas across different fields.