Land Hermit Crab Care Guide

Terrarium & humidity

• Maintain humidity at 70–80% or higher — hermit crabs breathe through modified gills that need moisture to function
• Use a glass terrarium with a secure, mostly-covered lid to retain humidity, monitored with a hygrometer
• Provide substrate deep enough (at least 15–20 cm/6–8 in) for burrowing and molting — a mix of sand and coco fiber works well
• Keep temperature in the range of 24–29°C (75–85°F) using an under-tank heater if needed
• Mist the enclosure daily to maintain humidity, especially in dry Canadian winter homes with forced-air heat
• Avoid wire cages, which cannot hold humidity and can injure crabs' legs

Shells & social behaviour

• Provide several extra shells in a range of sizes and opening shapes so crabs can upgrade as they grow
• Avoid painted or decorated shells, which can flake and be ingested or block movement
• Keep hermit crabs in groups of at least 2–3 — they are social and can become stressed in isolation
• Expect occasional shell-swapping disputes between crabs, which is normal behaviour
• Add new shells periodically even if current shells still fit, to give crabs the option to size up

Molting

• Expect crabs to bury themselves in substrate for weeks during a molt — this is normal, not illness
• Do not dig up or disturb a crab that has buried itself unless there's a clear sign of distress
• Leave molted exoskeletons in the enclosure — crabs often eat them to recover calcium
• Ensure substrate is deep enough for crabs to fully bury themselves before a molt
• Reduce handling and enclosure disturbance during suspected molting periods

Diet & water dishes

• Offer a varied diet of commercial hermit crab food, fresh fruits, vegetables, and occasional protein
• Provide two separate water dishes: one with dechlorinated fresh water, one with marine-grade saltwater (not table salt)
• Use dishes shallow enough or with a ramp so crabs can climb out and avoid drowning
• Avoid foods high in preservatives or copper, which can be toxic to hermit crabs
• Offer calcium sources like cuttlebone to support shell and exoskeleton health

Common problems

• Lethargy or a strong odor can indicate a dead crab inside its shell and needs immediate investigation
• Dropped or missing limbs can occur from stress or low humidity but often regenerate over successive molts
• A crab that stays out of its shell for extended periods may be searching for a better-fitting one — offer more shell options
• Consistently low humidity is the most common cause of illness and death in captive hermit crabs

Frequently asked questions