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Atlas / Library / Theridiidae / Western black widow
AdvancedNocturnal · sleeping now
Theridiidae

Western black widow

Latrodectus hesperusแมงมุมแม่ม่าย

Part of this is not on the page we cite. We opened it on 10 Aug 2026 and some of the degrees above are not stated there. The values above may still be right, but we cannot show you where they came from, and nobody here has checked them against a second source. Anything about a sick animal goes to a qualified exotic vet, not to a page. en.wikipedia.org

Photograph: Luke Padon · CC BY

Photographed by an observer on iNaturalist and published under a Creative Commons licence; the photographer and the licence are named under the image. It is not an animal of ours, and no animal was handled by us to produce it.

14:00
Day

Drag the sun. Western black widow is nocturnal, so what it is doing changes with the light.

National law is not global, and we hold no national wildlife law for any country, Thailand included. Check your own authority before buying or selling.

Back to the globe My keep

https://keepr.pet/husbandry/en/latrodectus-hesperus

‹ All husbandry guides
Temperature24–29 °C
Humidity45–60 %
Enclosure10×10×18
Diet7 days

The numbers

Temperature

152025303540 °C
24–29°Ambient

One ambient band, 24–29°C. This sheet states no warm side, no cool side and no night figure, so none are shown. Same scale on every sheet here, so two species compare by eye.

The sheet states24-29°C

Humidity

45–60%Target RH

The sheet states45-60%

Identity

Adult size

1.75 m1–1.5 cm
1520100400 cm
1–1.5 cmNose to tail, adult

The size the sheet states for a grown animal.

Why

Two drawings, because they answer two questions. The silhouette is at true scale against a 1.75 m person: it says how big this animal actually is, which no number does for someone who has never seen one. The bar under it is logarithmic and shared by every sheet here, so a 2 cm isopod and a 4 m python both stay readable on the same axis and two species can be compared at a glance.

Order / Family
Araneae
IUCN / CITES
IUCN not assessed; CITES not yet in our data
Difficulty
Advanced (experts only)
Commonality
Specialist keepers only
Adult size
Body ~1-1.5 cm female (black, red hourglass)
Lifespan
1-3 years (females)
Growth rate
Medium
Activity & niche
Nocturnal cobweb sit-and-wait ambusher
Temperament
Shy, not aggressive: but venom is dangerous
Venom / defense
Medically significant venom (latrotoxin, latrodectism) – advanced keepers only; NEVER handle

Enclosure and conditions

Enclosure

10 cm18 cm
warm hidewatersubstrate
50100150200 cm
10 × 10 × 18 cmWidth × depth × height
1dm² of floor
Warm side: not in our dataUVB: not in our data

Drawn from the stated numbers. Only what the sheet states is drawn inside.

Why

The rectangle carries the exact width-to-height ratio of the figures above it, and the ruler under it places that width on the 0–250 cm scale every sheet here shares, so two species still compare at a glance. Nothing is added that the sheet does not name: a lamp drawn on a sheet that never mentions one would be invented equipment. What the sheet leaves out is listed rather than left blank, because an empty tank reads as « none needed ».

The sheet states10x10x18 cm (vertical) with web anchors for one adult

Temperature
24-29°C
Humidity
45-60%
Min. enclosure
10x10x18 cm (vertical) with web anchors for one adult
Substrate
2-3 cm coco; web-anchor twigs/cork
Hides / decor / water
Twigs/cork for web, water via misting

What your climate adds

This sheet states a range to hold. Your local climate decides how much work holding it is. Pick the nearest city: nothing is sent anywhere, the choice stays in this browser.

Diet

Feeding rhythm

every 7 dAs the sheet states
4Meals in 28 days

Twenty-eight days, one row. Each band is a meal window.

Why

The windows widen as they go because the interval is a range: four meals after a 10–14 day cycle land anywhere between day 40 and day 56.

The sheet statesCrickets, flies, small roaches · 1-2 items weekly

Staple food
Crickets, flies, small roaches
Feeding frequency
1-2 items weekly
Supplements
Not required

Behaviour and handling

HandlingNever
CommunalNo: solitary/cannibalistic
Defense / stress signsDrops from web, plays dead, retreats

Reproduction

Life course

Day 0Hatch
1–3 yrLifespan in care
1 yrMinimum commitment
Sexual maturityNot in our data

Read from the lifespan and maturity the sheet states, for animals in care and not in the wild.

Why

The minimum commitment is the low end of that lifespan, and the reproductive window is what is left after maturity: both are subtractions on stated figures, not figures of their own.

Reproduction
Oviparous: papery egg sacs with hundreds of spiderlings; not live-bearing

Common health problems

Common health issues
SignsDehydration; bad molt
Red flags / quarantine
SignsEscape-proof labelled enclosure; tools only; verify legality/competence; QT wild-caught

Good to know

  • Produces some of the strongest silk of any widow, used to suspend prey much larger than itself

What it needs

Enclosure at least 10 × 10 × 18 cmbecause enclosure10x10x18 cm (vertical) with web anchors for one adult
A thermometerbecause temp24-29°C
A hygrometerbecause humidity45-60%

Every line above is deduced from a value this sheet states, and names which one. Nothing here is a general recommendation.

Sources

Others in this group

What this sheet states

100%
TemperatureHumidityEnclosure sizeActivityOriginDietSourcesUVB

Every field this product runs on is stated here. That is not a claim that the values are right: it says what the sheet states, not whether it is true. Whether a human has read it is the badge at the top of this page.

UVB is measured but does not count: it is absent from 421 of 678 sheets, and on most of them that is not a gap, since a nocturnal snake's sheet has no reason to state a UV index. Counting it would call the library incomplete without cause.