The Islamic rulings regarding the consumption of birds and animals are understood through two main criteria: For birds, the standard is that the meat of predatory birds, which have talons and use them to catch and eat their prey, is not permissible. Birds like hawks, falcons, crows, bats, vultures, ravens, eagles, and kites, which hunt with their talons, are forbidden to eat. However, birds that have talons but do not use them as weapons and do not obtain their food with them, such as pigeons, are permissible to eat.
For land animals, the determining factor is their molar teeth. Animals that use their molars as weapons are forbidden to eat. This includes animals like wolves, foxes, cats, lions, tigers, hyenas, elephants, dogs, weasels, squirrels, leopards, monkeys, and ferrets. However, animals that have molars but do not use them as weapons, such as camels, which feed on grass and straw, are permissible to eat.
The third category includes animals that are inherently filthy or impure by nature. These animals do not catch their prey with claws or molars but are considered impure by their nature. This category includes creatures like hedgehogs, mice, scorpions, snakes, ticks, frogs, land and sea turtles, moles, and various types of flies. Additionally, parts of slaughtered animals, such as the testicles, gallbladder, bladder, and genitals, are also considered impermissible to eat and are regarded as makruh (disliked but not strictly forbidden). However, the liver and spleen of animals are permissible to eat.