We've talked before about using special plantings, water, and feeders to attract birds to your garden. This afternoon I'd like to tell you about a less well-known way to attract birds. It' s by putting out eggshells. Many birds eagerly consume them. Perhaps it is a method of replacing calcium lost by females and egg-laying, though I have seen males eat the shells too. Anyway, I have had at least eight different species of birds come to eat the eggshells. Here is how it's done. You should save your eggshells and rinse them in water, then cook them lightly on the baking pan in the oven; set at a low temperature until they are dry but not brown. This sterilizes them and makes them brittle. You can crumble them into bite-sized pieces and spread them on the ground, a rock, or a bird feeder. You may find them so popular you want to go to your favorite restaurant to ask for more eggshells.
解析
Why are the birds attracted to eggshells?
细节题。展示提到Many birds eagerly consume them．即“很多鸟类都很急切地想吃掉他们”。本题中的consume与eat是同义替换。因此，正确答案是B。