If your home has  a backyard or even a balcony, you may already offer feeders or baths to your avian neighbours, but have you ever thought of offering them yarn or fibre? Birds can use short scraps of yarn and small tufts of fluff in building their nests.  Cut yarn into 10 to 20 cm lengths and put them into suet cages. It’s like a homebuilding centre for birds! Find out what other materials make good nests in  the Cornell Lab of Ornithology‘s excellent guide to attracting birds.