Instructions
Vary your suet feeding routine by moving your feeders around, feeding at different times of day and even stopping feeding for a week at a time. Crows quickly get used to a routine and this will help throw them off, at least temporarily.
Put out raw, unsalted peanuts, which crows love, in a different area of your yard from where your suet feeder is located. This will help draw away the crows from your feeder.
Enclose your suet feeder inside a wire mesh cage with holes large enough to let small birds in, but too small for crows to fly through.
Use a feeder made of a smooth wood-substitute product like Polywood or hard resin. Large birds like crows will find it difficult to gain a foothold on such a feeder because it will be too slippery to hold their weight.
Use a "suet sandwich" which consists of two slabs of fake wood (hard resin) sandwiched together, inside which you can insert suet. This can be suspended from a pole. Crows have a hard time getting a foothold on the device, or inserting their beaks into the narrow gap between the slabs, but smaller birds like woodpeckers have no problem with it.
How to Protect Suet Feeders From Crows
Suet is animal fat, typically obtained from beef or mutton. It is a common bird food for backyard feeders, and putting up a suet feeder will attract birds to your garden in the winter months when other high-calorie foods are often lacking in a bird's natural environmental. However, suet will also attract birds that you might not want at your feeder, such as crows, which may deter smaller birds from visiting the feeder.