How often and how much should I feed my hermit crab?
Adult hermit crabs need food every 24–48hours, about 1–2teaspoons (5–10g) of mixed diet per feeding.
Adult feeding frequency and portion
Feed an adult hermit crab once every 24–48hours, offering about 1–2teaspoons (5–10g) of mixed food per feeding. This amount fills roughly 10% of the crab’s stomach capacity and leaves room for water intake. If the crab is highly active or the enclosure is kept at the upper end of the temperature range (85°F/29°C), you can increase to 2teaspoons. Conversely, in cooler conditions (75°F/24°C) or if the crab appears sluggish, drop to 1teaspoon.
Measure the food with a kitchen scale or a level teaspoon; consistency helps you spot changes in appetite. Offer the portion on a shallow dish no larger than 2×2inches so the crab can easily reach it. Replace uneaten food after 12hours to prevent mold, especially in a humidity‑controlled enclosure at 70–80%.
- 24–48hours between feedings
- 1–2teaspoons (5–10g) per adult
- Replace leftovers after 12hours
Feeding by life stage
Juvenile crabs (0–6months) should be fed every 12–24hours, with ½teaspoon (2–3g) of finely chopped food. Their rapid growth means they can double their intake in a week, so monitor weight weekly. Provide extra calcium sources like crushed cuttlebone twice a week to support exoskeleton formation.
Adults, as described above, eat every 24–48hours at 1–2teaspoons. If you notice a molt in the next 3–5days, add a small protein boost of ¼teaspoon (1g) of boiled egg or fish. This helps supply the nitrogen needed for new shell formation.
Senior crabs (7years and older) often reduce intake to once every 48–72hours, preferring ½teaspoon (3–5g) of soft foods. Offer soaked fruit or papaya to aid digestion, and keep water sources warm (around 78°F/26°C) to encourage drinking.
- Juveniles: feed every 12–24h, ½tsp
- Adults: feed every 24–48h, 1–2tsp
- Seniors: feed every 48–72h, ½tsp
Measuring, transitioning, and treats
Use a digital scale that reads to 0.1g for precise portions; 1tsp of mixed diet typically weighs 5g. When introducing a new protein (e.g., shrimp), start with ¼tsp (1g) mixed into the regular diet for three consecutive feedings. This gradual approach lets the crab’s gut flora adjust without stress.
All fresh foods must be rinsed in dechlorinated water and then soaked for 5minutes in a 1:1 salt‑to‑fresh water solution (½cup each) to mimic the brackish environment. After soaking, pat dry and place on the feeding dish. Never offer raw meat that has been left at room temperature for more than 30minutes.
Treats should never exceed 10% of total intake. Offer a small piece of unsalted almond (≈0.2g) or a slice of mango once a week. Rotate treats to keep the crab interested and to provide a variety of micronutrients.
- Scale to 0.1g accuracy
- New food: ¼tsp (1g) for 3 feedings
- Treats ≤10% of diet
Common feeding mistakes and how to spot them
Overfeeding is the most frequent error; excess food rots quickly in 70–80% humidity, leading to ammonia spikes. If you see a white, powdery film on the substrate or a sour smell, thin the portions by 25% and clean the dish daily. Moldy food also attracts pests like springtails, which can stress the crab.
Underfeeding shows up as a thin, translucent exoskeleton and reduced activity. Weigh your crab monthly; a loss of more than 0.5g over two weeks signals a calorie deficit. Increase portion size by ½teaspoon and add a protein source for the next three feedings.
Improper hydration mimics feeding problems. If the crab spends more than 10minutes near the water dish without drinking, check that the water temperature is 78°F (26°C) and that the dish is shallow (≤0.5in depth). Adjust humidity to stay within 70–80% and watch for lethargy, which often resolves within 48hours after correcting water quality.
- Watch for mold and ammonia
- Monitor weight loss >0.5g/2weeks
- Ensure water at 78°F (26°C)
Keep reading about Hermit Crab: Hermit Crab care sheet
Related questions
Can I feed my hermit crab fruit every day?
Fruit should be limited to 1–2times per week, about ¼teaspoon (1g) per serving. Daily fruit can cause excess sugar and soft stools.
How much water should I provide?
Offer two shallow dishes: one with dechlorinated fresh water and one with a 1:1 salt‑to‑fresh mix. Each dish should hold ½cup (120ml) and be refreshed every 24hours.
What signs indicate my crab is not getting enough calcium?
A pale, brittle exoskeleton and prolonged molting periods (more than 7days) suggest calcium deficiency. Add a pinch of crushed cuttlebone to the diet twice weekly.
Not veterinary advice. This guide covers husbandry — housing, feeding, cleaning and handling. If your hermit crab is injured, off food unusually long, or behaving abnormally, contact a veterinarian.