For pests that walk, run, or burrow, more extreme physical measures might need to be taken. Until the marijuana plant develops a hard stem, all manner of rodents, rabbits, and possibly even raccoons may decide to snack on your marijuana plants.
Mannabis growers experience problems with rabbits, hares or wombats and wallabies for Australian growers. Wombats are small and tend to burrow underground and eat at the roots, whereas rabbits and wallabies will trample and eat the plants, as they do most leafy things they encounter. Placing a hard object around the base of the marijuana plant, such as a coffee can with both ends removed, or anything else with similar hard shell properties, helps against most burrowing animals.