Do helicopter rotors have anti-ice systems like propellers and wings?
Yes, helicopter blades are no different from wings and propellers when it comes to ice, and there exist rotor de-ice and anti-ice systems for helicopters that require the ability to fly in known icing conditions, typically military types. Some examples include the Sikorsky S-92 and MH-60, and the Kamov Ka-50.

Rotor anti-icing systems are usually electric devices like heated mats, which are mechanically simpler that typical fixed-wing solutions like pneumatic boots and bleed-air-heated leading edges.

Not only the blades require anti-ice systems, however: elements like the engine intakes and air data sensors also need to be kept free of ice just like in fixed-wing aircraft.