Easy to open to refill by just fastening the clip that holds the lid in place.
Garden birds that enjoy eating suet are: Sparrows, Blue Tits, Great Tit, Long Tail Tit, Chaffinch, Bullfinch, Greenfinch, Goldfinch, Thrush, Blackbird, Robin.
It is always worthwhile cleaning your feeder occasionally with warm water & a mild detergent or a disinfectant solution to avoid a build-up of bacteria.