Possible Clues:

• Moth larvae
• Some creep munching gum leaves
• Provide posts for animals
• They make tracks for these garden bugs
• Crate's broken down, support's in vehicles making tracks
• Many-legged larvae tracks
• They provide columns - in Grub Street?
• Insects react badly when colliding with posts
• Tractors! The bane of the Greens
• Gives food with support for larvae