When selecting a caged feeder, it is important to choose the correct style for either big birds or grey squirrels.

For keeping squirrels out, the mesh strength is the imporant factor, as grey squirrels can be quite destructive and break thin mesh.
Distance from cage to feeder is not so important for squirrel deterrent (as long as they can’t get their head through the gaps)
For keeping big birds out, the important factor is distance between cage and feeder – the big birds can get their heads and beaks through even small mesh, so a gap of at least 2 inches (5cm) is best.
We are often asked for a cage feeder that will let woodpeckers and blackbirds access the food whilst also keeping out pigeons and starlings. This is very difficult as the birds are very similar sizes.
An alternative approach for preventing squirrels and big birds getting to the food is a pest proof gravity feeder.