What animals has secretion?

Many animals produce secretions for various purposes. For example, mammals like cows and goats secrete milk to nourish their young, while amphibians such as frogs secrete toxins through their skin as a defense mechanism. Insects like ants and bees produce pheromones for communication, and reptiles like snakes may secrete venom to subdue prey. Additionally, many animals secrete mucus for protection and lubrication.