Husbandry basics
This is not a care sheet, and it does not replace one. It is the short list of things that decide whether a tarantula lives, written down because Exuvia enforces them in software and a keeper deserves to know what the app is doing on their behalf.
Several of these are counterintuitive. Two of them are the opposite of what a new keeper's instinct says.
Feeding is an offer, not a meal
Tarantulas refuse food routinely and healthily. A spider may go weeks — in some species months — without eating and be entirely fine.
So putting prey in an enclosure records that prey was offered, not that the animal ate. You usually do not know the outcome at the moment of offering; you find out the next day. Exuvia keeps those as separate facts, because collapsing them into "fed: yes" throws away the most diagnostic information a keeper has.
Uneaten prey comes out within about a day
A live cricket left in an enclosure can injure or kill a tarantula. That is especially true of an animal about to moult, which cannot defend itself.
Exuvia treats this as a safety task rather than record-keeping: an offer still unresolved after 24 hours is surfaced for checking, prominently.
A spider that has just moulted must not be fed
This is the one that matters most. After moulting, a tarantula's exoskeleton and fangs are soft. It cannot eat, and it cannot defend itself. Live prey offered during this window can kill it.
The rest period scales with size and species — around seven days as a default, fewer for slings, up to about fourteen for large adults. Record a moult in Exuvia and that animal disappears from feeding prompts until the period has passed. There is no override, and that is deliberate.
Refusing food is information, not a problem
A spider entering premoult stops eating, and keepers often do not notice until the moult happens. Spotting it early explains otherwise worrying refusals and tells you to stop offering food.
Exuvia watches for three or more consecutive refusals since the last confirmed meal, or a bald patch seen in the last three weeks. Recording a moult clears the signal, because a signal that predicts a moult should stop predicting one that has already happened.
Other genuine premoult signs that Exuvia does not track: a darkening abdomen, the burrow being sealed, lethargy, and heavy webbing of the substrate.
Water matters more than food
Dehydration kills more tarantulas than underfeeding does. A water dish in a warm room needs refilling every few days — sooner for arboreal setups and small dishes.
Exuvia tracks water per enclosure rather than per animal, because one dish serves one tank and that is how a keeper actually works. An unchecked dish is assumed empty rather than assumed full.
Old World and New World
The single most important distinction in the hobby, and it governs how an animal is handled.
| New World | Old World | |
|---|---|---|
| Urticating hairs | Yes, flicked as defence | None |
| Venom | Medically insignificant | Can be medically significant |
| Speed | Generally slower | Generally very fast |
| Temperament | Generally calmer | Generally defensive |
An Old World species is not a beginner animal. Exuvia says which one you are looking at on every screen an animal appears on, and on every species page here.
Slings and adults eat differently
A spiderling and an adult of the same species are on entirely different schedules.
| Stage | Typical interval |
|---|---|
| Sling | 5–7 days |
| Juvenile | 7–10 days |
| Adult | 10–21 days, depending on species |
Moults are the growth record
A moult is the only reliable point at which to measure a tarantula, and the shed skin is how the animal is sexed. Moult intervals lengthen predictably with age.
One thing worth knowing before you sex an animal: a mature male stops moulting, becomes restless, stops eating, and dies within roughly a year. That is the end of his normal life, not something going wrong.
These numbers are defaults, not facts
Every figure on the species pages — feeding intervals, temperature, size, lifespan, temperament — is a genus-level default. Several are labelled genus estimate precisely because they are.
Where a value has never been reliably sourced, the page says Not recorded. That is deliberate. Invented precision in a care app is dangerous, and a wide range or an admitted gap is more honest than a plausible number nobody stands behind.
Your animal in your room beats all of it. In Exuvia every one of these values is yours to edit.