Fat balls are made from suet mixed with bird foods, such as seeds, nuts and mealworms. They vary in price, with some as low as £6 for 50 balls, and others costing almost three times as much. We wanted to know which brands were most popular with birds.
We tested 12 different brands over the course of 12 weeks. Our expert tests observed the birds feeding from a hide. We recorded both the numbers and the species of birds seen feeding, with at least three hours of monitoring for each fat ball on test. We also tested how well each brand stood up to the weather and whether they fell apart, leaving an ugly mess under the bird feeder that can attract rats.
Use the right feeder
Feeders for fat balls come in an enormous range of shapes and sizes. We'd advise you look out for one that doesn't contain too many balls, so that the birds can eat them before they start to disintegrate. Squirrels will remove fat balls wholesale, so do invest in a squirrel-proof bird feeder if this is likely to be a problem.
Site your feeder close to cover, such as a leafy bush or tree, so that small birds can hop on and off quickly to avoid predators. Place it where local cats won't be able to access it - find out more about coming into your garden.
We often thinking of feeding the birds as a winter job, but actually their winter food sources, such as berries and nuts, will often last them through to mid-winter or beyond. February-April is an important time to feed birds as winter food sources run low and summer insects are yet to emerge.
The most popular fat balls in our trial had high suet content and tended to be quite soft. This made them easy for the birds to eat, but also meant they did have a tendency to fall apart more easily. Don't worry if this happens. If you have a problem with rats, pick up the pieces, otherwise ground-feeding birds, such as chaffinches, blackbirds and starlings, will appreciate the treat.
These tiny blue and yellow birds are a favourite garden visitor, and will happily hang on feeders to feast on nuts and seeds in fat balls.
With a smart black and white head, and a yellow chest with a black stripe, great tits are easily distinguished from the smaller blue tits.
In delicate shades of brown and grey, these elegant little birds will visit a feeder and enjoy bopping around the base to catch any falling crumbs.
These have a distinctive long tail and buff or pinkish body, making them extremely pretty. They like to fly in small flocks.
With its orange chest, the robin is one of our best-loved birds. It will manage to hang from a feeder, especially if it has a stiff wire cage to support it.