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New Caledonian crows visit fallen tree trunk that are covered in holes made by large wood-boring beetle grubs. Crows are very intelligent and listen out for the sound of grubs chewing away inside their burrows. As the crow does not have the long tongue of a woodpecker, a tool is needed to spear the insect grubs. By inserting a twig deep into the hole in the tree trunk, a crow can pull out enormous grubs. Some crows may even have a favourite twig and carry it with them. Also, a group of crows may all gather round one grub-filled log and use twigs to irritate the grubs enough that the bug reacts and bites the twig with its powerful jaws. The crows then haul the grubs out of their holes like fish. Young birds watch experienced adults to see how it is done, but it takes about a year to learn the skill properly.