Minecraft wiki entry for Damage, associated text: Withers and wither skeletons inflict the Wither effect with their attacks (the wither skulls do not inflict the effect on easy difficulty). This darkens the health bar to × 10 on Survival and × 10 on Hardcore, while inflicting damage over time. The effect deals 1 every 2 seconds (40 ticks) for the wither skeleton's attack (level I), and every second for the Wither's skulls (level II). Wither roses also inflict the Wither effect to any mobs colliding it. Players also get the Wither effect after eating suspicious stew made out of wither rose or when hit by potion or arrow of decay.‌[Bedrock and Education editions only] Unlike Poison, withering can kill on any difficulty level, and the darkened health bar makes it harder to keep track of the damage, which the only way is seeing the white spark on the left of the heart.