From a young age, children are deeply curious about animals. Stable patterns exist in the types of attitudes children display towards different kinds of animals: they love pets, value animals that are beautiful, and fear snakes and spiders (Borgi & Cirulli, 2015, https://doi.org/10.2752/089279315X14129350721939). Until recently, we’ve known little about what children think about the moral standing of animals, particularly relative to other entities, including humans. In this review, we synthesize the literature examining children’s perceptions of the moral worth of animals. We present factors about the animal, and factors about the judge (the child), shown to impact children’s evaluations of animal moral worth. Based on current evidence, we make the claim that children grant animals a high moral standing early on in childhood, but that this decreases during late childhood, throughout adolescence, and into adulthood. We provide some suggestions for the cognitive and cultural mechanisms that might drive these differences, and make recommendations for the field going forward.