Hedgehog needles, or spines, serve several important functions.
Defense
The sharp needles deter predators. When threatened, a hedgehog curls into a tight ball, presenting a formidable barrier.
Other Functions
Camouflage: Can blend with surrounding vegetation.
Thermoregulation: Trap air to insulate against cold.
Communication: Raising or lowering spines may signal mood or status to other hedgehogs.
Overall, these spines are a complex adaptation that significantly aids survival.