Carnivores, whatever their size, are all hunters. Some hunters lay in wait for their prey. The spider is like this. The lion, by contrast, aims to catch its prey by the speed of its running. Other carnivores simply find other animals along their route and eat them. A hedgehog eats slugs and other animals in this way. Birds of prey such as the kestrel and the sparrow hawk are carnivores and fish that eat snails are also carnivores.
As you can see, it is important not to think that a carnivore is just a large animal with large pointed teeth and sharp claws.