Chicken thighs and legs are considered dark meat, meaning those cuts contain a bit more fat than white meat. And because fat = juiciness, chicken drumsticks are at a lower risk of drying out if the temperature goes above 165°F. This is especially so with skin-on drumsticks. I've had some drumsticks go up to 180°F and found the meat to still be really tender and juicy, so don't stress out that your meal is ruined if you don't pull them at 165°F exactly.