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Mexican Red-Knee Tarantula
Brachypelma hamorii
The Mexican red-knee is the tarantula most people picture when they picture a tarantula — a dark body offset by bright orange-red joints on each leg, a slow, deliberate walk, and a famously calm temperament that has made it a mainstay of film and television for decades. That same popularity drove serious wild-collection pressure through the 1980s, and Brachypelma hamorii is now protected under CITES Appendix II, so a legitimately sourced pet is almost always captive-bred rather than wild-caught — worth confirming at purchase. Compared to the faster-growing, more defensive Chilean rose tarantula common as a first spider, the red-knee is slower to mature, calmer in temperament, and one of the longest-lived invertebrates commonly kept as a pet, with females routinely outliving the dog or cat a keeper might have gotten at the same time.
Females 20-30 years; males typically 5-10 years and die within a year or so of maturing — one of the largest sex-based lifespan gaps in the hobby
5-6 inches (13-15cm) leg span at full maturity
Pacific coastal dry forest of Jalisco, Colima, and Michoacán, Mexico
Husbandry
- A terrestrial enclosure roughly three times leg span in length and twice in width, low rather than tall — this is a ground-dwelling species, and excess height mainly creates fall risk from a species with a leg span like this one's
- Source: British Tarantula Society husbandry guidance (checked 2026-01-15)
- 75-82°F (24-28°C) ambient; tolerates brief drops into the high 60s°F (upper teens °C) without issue given this species' subtropical, seasonal native range
- Source: British Tarantula Society husbandry guidance (checked 2026-01-15)
- 60-70% ambient with a shallow water dish always available; this species does not require the very high humidity of rainforest tarantula species and tolerates drier stretches well
- Source: British Tarantula Society husbandry guidance (checked 2026-01-15)
- Appropriately sized crickets or roaches offered every 5-10 days for an adult, less often than a fast-metabolism species — red-knees are famously slow growers and slow eaters, and an adult can go a surprisingly long stretch between meals without concern
- Source: British Tarantula Society husbandry guidance (checked 2026-01-15)
- Strictly solitary — tarantulas are not a communal species and will predate a cage-mate; adults are only ever placed together briefly and under close supervision for deliberate breeding attempts
- Source: British Tarantula Society husbandry guidance (checked 2026-01-15)
- 3-4 inches (7-10cm) of coco fiber or a coco fiber/topsoil mix, deep enough to allow some burrowing behavior even though this species spends most of its time on the surface
- Source: British Tarantula Society husbandry guidance (checked 2026-01-15)
Handling
Red-knees have a genuinely calmer temperament than many popular pet tarantula species and are one of the species sometimes handled by very experienced keepers, but handling always carries real risk in both directions: a fall from even a modest height can rupture a tarantula's abdomen and be fatal, and this species — like other New World tarantulas — will kick urticating hairs from its abdomen when stressed, which cause significant skin and eye irritation to the keeper. The responsible default, and what most experienced keepers actually recommend even for a calm species like this one, is to treat it as a display animal moved only with a catch cup, not a hand, and to never handle over a hard floor or from any real height.
Setting up the enclosure
Because this is a ground-dwelling, slow-moving species rather than an arboreal one, the standard setup is deliberately low and wide rather than tall — a tall enclosure mainly adds fall risk without adding usable space for a spider that doesn't climb much. A shallow water dish, a hide (half a flowerpot or cork bark works well), and a few inches of substrate for occasional light burrowing cover the essentials; red-knees don't build the elaborate deep burrows some other terrestrial species do, and mostly rest in the open or in a shallow scrape once settled.
Why the lighting and heating numbers matter
No UVB or specialized lighting is needed for tarantulas generally, and this species in particular tolerates a wider ambient temperature range than many tropical invertebrates because its native dry forest habitat has a real seasonal temperature swing, including a distinct cool dry season. That tolerance is part of why red-knees are considered forgiving of an average room's fluctuations in a way that a strictly tropical rainforest species would not be — a heat mat or lamp is rarely necessary in a normally heated home, and can create dangerously dry, overheated microclimates if used carelessly with an animal this size in a relatively small enclosure.
Feeding in practice
Feeding frequency drops sharply with age and size — spiderlings eat small prey items multiple times a week to fuel rapid early growth, while a mature adult red-knee may only need feeding every one to two weeks, and refusing food for weeks at a stretch before or after a molt is normal rather than a red flag on its own. Uneaten live prey is removed after 24 hours since a cricket left loose can stress or, rarely, injure a tarantula that's in a vulnerable post-molt state. This unusually slow metabolism and growth rate — red-knees can take 8-10 years to reach maturity — is one of the most distinctive things about keeping this species compared to faster-maturing tarantulas.
Common mistakes with this species
The most common mistake is handling this species simply because its calm reputation makes it feel safe, and then being caught off guard by a defensive hair-kicking event or a fall — both real risks regardless of temperament. The second is overfeeding or feeding on a schedule set for a faster-metabolism species, which doesn't suit a naturally slow eater and can lead to obesity or, more often, wasted uneaten prey items left to stress the spider. The third is buying without confirming captive-bred provenance, given this species' CITES Appendix II status and history of wild collection pressure.
Lifespan and what to expect
The lifespan gap between sexes is the single most important expectation-setting fact about this species: a female red-knee bought as a young juvenile can realistically become a decades-long commitment, often outliving the keeper's other pets and sometimes changing households along the way, while a male reaches maturity faster and lives only a fraction as long after his final molt. Growth itself is slow and unhurried at every life stage compared to faster-maturing tarantula species, so a keeper expecting rapid visible size change from a red-knee sling will be waiting years, not months, to see it.
Temperament in more depth
Individual temperament varies even within this generally calm species — some red-knees tolerate a light, brief hand contact without any defensive response, while others kick hairs or adopt a threat posture (raised front legs, exposed fangs) at far milder provocation, and a keeper should always let the individual spider's behavior, not the species' general reputation, dictate how much space to give it. A threat posture or a rapid retreat into a hide are both normal, healthy defensive responses rather than signs of a poorly socialized animal — tarantulas don't bond or tame in the way mammals do, and consistent calm handling reflects a naturally even-tempered individual more than any training on the keeper's part.
Signs of good health
- Full leg span with all eight legs and pedipalps intact, moving with the species' normal slow, deliberate gait rather than dragging or favoring a limb
- A plump, rounded abdomen — not shriveled or unusually wrinkled — indicating good hydration and recent feeding
- A clean, intact urticating-hair patch on the abdomen (a bald patch there is a normal defensive-use mark, not automatically a health problem, but a raw or wet-looking patch is)
- Successful, complete molts with the old exoskeleton (exuvia) shed cleanly, and the tarantula resuming normal activity within a couple of weeks
- Normal burrowing/webbing activity and a healthy feeding response when prey is offered
Common problems
12 common invert problems are tracked for this species; 0 have full guides published so far.
Recommended gear for Mexican Red-Knee Tarantula
Equipment categories that are genuinely correct for this species' welfare needs — see the full Gear Guide for the complete list.
Digital infrared temperature gun
Measures actual basking SURFACE temperature, not just ambient air — a stick-on dial thermometer reads air temp, which is a poor proxy for the surface temp that drives digestion and thermoregulation.
Simple, easy-to-sanitize quarantine enclosure
A separate, minimal, easy-to-bleach-and-rinse enclosure (as opposed to the animal's permanent bioactive setup) makes a genuine multi-week quarantine period realistic — see the Quarantine Timeline Planner tool for recommended duration.
Digital gram scale
Regular weigh-ins are one of the earliest, most objective ways to catch a developing health problem (weight loss often precedes visible lethargy) — a cheap kitchen-grade gram scale is accurate enough for routine tracking.
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This is general educational care information, not veterinary diagnosis. For a sick or injured animal, see a qualified exotic-animal vet promptly — especially for anything acute (not eating combined with lethargy, breathing changes, bleeding, or any sudden behavior change). Nothing on this page substitutes for an in-person exam.