A sensible rule of thumb

For many terrestrial tarantulas, an enclosure around two to three times the leg span in length and width is a practical starting point. Height should be controlled so a fall is unlikely to injure the spider.

Arboreal species need more vertical structure, while fossorial species need substrate depth. The right enclosure is always species-led.

Spiderlings need smaller setups

Tiny spiderlings usually do better in smaller, secure containers because they can find prey more easily and you can monitor them without conducting a search-and-rescue mission every feeding day.

Security matters

Ventilation, lid security, moisture control and escape-proof gaps matter more than buying the largest enclosure possible. If a feeder insect can stroll out, a determined spiderling may follow.