A bunch of snails and slugs can devour your whole plant, leaves, buds and all if left unchecked. Some slugs can even go underground to attack plant roots. Since both are common garden pests that will eat almost any kind of plant, they are usually a problem for outdoor growers but not so much for the indoor grower. Seedlings are especially vulnerable since these molluscs prefer munching on tender foliage and stems. These nocturnal pests can eat several times their weight, mostly at night to avoid predators.