For Suet Feeders, use only suet with a high percentage of actual suet (beef/animal fat). Since suet feeders have become popular, like commercial birdseed mixes, suet products has been cheapened by adding inexpensive less appealing filler mixes so it is important to search out quality suet. Good quality suet is soft and looks like lard with some sunflower in it or peanut parts – poor quality suet is hard and packed with millet/cracked corn and other inexpensive fillers. Poor quality suet really is over 90% inexpensive fillers and very little suet.
Also consider beef suet from your local butchers counter or freezer.
Suet feeders are an alternate food source for birds so they typically will not generate the bird activity and visits compared to a seed feeder with quality seed in it.
Suet feeders can be used throughout the year, however they typically attract more birds during winter months when food supply is lower and the high fat content of suet provides a good energy source during the colder months.
Just like seed feeders, it usually takes a while for birds to acclimate to a New suet feeder so using quality suet and following good bird feeding tips is important.