Hedgehogs and tenrecs have some similar housing needs (temperature control, hiding places, substrate that allows natural behaviour), but there are also important species- and regional differences. Below is what current literature and care guides suggest, and pointers on what you should aim for to ensure welfare.

Key Housing Features

Before discussing sizes, there are several essential enclosure features:

• Solid floors:
  Wire bottoms are generally unsuitable because they can injure feet. Solid or smooth bottoms with appropriate substrate are preferred.
• Escape prevention:
  Bar spacing must be small enough that tenrecs (which are adept climbers and very flexible) cannot squeeze through; escape-proof lids are needed.
• Hiding places / nest boxes:
  Multiple shelters, tubes, logs, dark retreats are important for both: for rest, protection, nesting.
• Climbing / enrichment:
  Especially for tenrecs. Branches, ropes, shelves; even hedgehogs benefit from enrichment.
• Substrate & bedding:
  Safe materials (paper, aspen, untreated soft woods, coconut fibre, etc.), cleanable, non-toxic; avoid cedar, very dusty shavings; sufficient depth to allow burrowing where species naturally dig.
• Temperature & ventilation:
  Warm, stable temperatures (species dependent), gradients so animals can move to preferred micro-climate; avoid draughts and overheating; good ventilation but avoidance of excessive airflow in cold climates.
• Size matters for behaviour:
  Enough space for exercise, exploration, foraging behaviour; minimum sizes often given, but “larger is better” is a frequent admonition in hedgehog/tenrec care literature.

Hedgehogs: What the Guides Say

From sources in veterinary care, rescue, hobbyist communities, care and husbandry websites, here are typical recommendations for hedgehog enclosures (especially captive or pet hedgehogs, e.g. African Pygmy Hedgehog) in non-wild contexts:

• Minimum floor area:
  Many care guides suggest 2 × 3 feet (~61 × 91 cm) minimum floor space. That provides enough room for basic movement, a wheel, resting / nesting space, and feeding/water stations.
• Recommended area:
  Some hobbyist and humane‐care sources suggest 4 square feet (≈ 24 × 24 in ≈ 61 × 61 cm) as an absolute baseline, with larger being much better.
• Height / wall height:
  Walls high enough to prevent escapes; hedgehogs can climb or push things to get over barriers. Glass aquaria or smooth solid walls help avoid injury.
• Legal / welfare obligations:
  In places like the UK (Animal Welfare Act) or similar jurisdictions, owners must meet animals’ “behavioural needs,” including the ability to express natural behaviours (foraging, exploring, nesting). Thus, cage/enclosure should enable this. Actual minimum cage size may not be codified but failing to provide adequate space can be a welfare offence.

Tenrecs: Specific Requirements

Tenrecs are more varied in behaviour and morphology than hedgehogs, and many sources stress that tenrecs need more complex enclosures to allow climbing, burrowing, hiding, and sufficient floor space. Here’s what care guides and case studies report:

• Minimum recommended cage size:
  Many tenrec care guides suggest a cage with dimensions of 36 in × 18 in × 18 in (~91 × 46 × 46 cm) as a base minimum for some spiny or small tenrec species. Many keepers and guides recommend using vivariums that are at least 4 feet in length (≈ 120 cm) to provide sufficient space for night-time activity, exploration, feeding, enrichment. Height also matters: at least ~45 cm (about 18 in) for climbing behaviour.
• Zoo or research enclosures:
  In the zoo study “Maintenance and reproduction of tenrecs at … Tsimbazaza”, enclosures for various tenrecine species used wooden box cages measuring 100 × 50 × 55 cm deep (~1 m × 0.5 m × 0.55 m) with nestboxes inside. Smaller species (Microgale etc.) used smaller cages (e.g. 58 × 55 × 55 cm) but still with adequate depth and nesting material.
• Vertical space and climbing:
  Because many tenrec species climb, enclosures with some vertical dimension (shelves, branches, climbing surfaces) are preferred; height of at least ~18 in (~45 cm) is common in recommendations.

Comparing Hedgehog vs Tenrec Enclosures

Legal Requirements: What to Watch Out For

There is no one global standard or law that dictates exact cage sizes for hedgehogs or tenrecs. However:

• In many countries, animal welfare laws stipulate that pet / captive animals must be kept in conditions that allow “normal behaviour,” “adequate space,” and “freedom from discomfort.” If an enclosure is too small or lacks key enrichment, it may violate those laws.
• Protected species (for example, wild hedgehogs in Europe) may not legally be kept in captivity or pet settings; even where permitted, there may be specific licensing / welfare inspection obligations.
• Institutional (zoo / research) settings often follow guidelines from professional bodies (WAZA, EAZA, AZA, local zoo association) that have detailed standards for minimum enclosure sizes, crowding, environmental enrichment, nesting, etc.

Practical Tips: What to Aim For

Given the gap between minimum acceptable space and ideal conditions:

• Always choose an enclosure larger than the minimum wherever possible. More space allows better expression of natural behaviour, healthier exercise, lower stress.
• Design enclosures with enrichment: hiding, climbing, digging, exploring. Space used only for a wheel or nest is less effective than space that allows exploration.
• Monitor animal behaviour: pacing, over-sleeping, excessive restlessness, weight gain/loss can signal enclosure is inadequate.
• Maintain temperature and ventilation carefully; larger enclosures can have temperature gradients; ensure heating and insulation are adequate.
• Ensure secure structure: small bar spacing, solid joints, escape-proof lid, safe materials, no toxic woods or varnishes, no sharp edges.

Summary

While there is no universal law that gives one exact size for all hedgehog or tenrec enclosures, the consensus in care literature is quite clear:

• For hedgehogs: aim for at least 2×3 ft floor space (~61×91 cm), solid bottom, hiding/nesting, exercise wheel, etc.
• For tenrecs: enclosures often need to be larger, both in floor area and height, especially for species that climb or need more vertical complexity; many keepers suggest vivariums of 4 ft or more in length, heights ~45 cm, and secure solid or closely barred walls.

Legal or welfare standards rarely mandate exact dimensions but require that animals can express natural behaviours and are kept in healthy, comfortable conditions, which means these minima are not optional if you want to comply with good welfare.

Sources

VCA Animal Hospitals. Hedgehogs – Housing.
https://vcahospitals.com/know-your-pet/hedgehogs—housing

Critter Connection. Cage Selection Requirements for Hedgehogs.
https://blog.critterconnection.cc/cage-selection-requirements

Green Feathers UK. Can you keep a hedgehog as a pet? (overview of UK welfare requirements).
https://www.green-feathers.co.uk/blogs/news/can-you-keep-a-hedgehog-as-a-pet

Quill Valley Exotics. Tenrec Care Guide.
https://www.quillvalleyexotics.com/tenrec-care-guide.html

Ali’s Menagerie. Lesser Hedgehog Tenrec Care.
https://www.alismenagerie.co.uk/care/mammals/lesser-tenrec-care

Limoges, P. (1994). Maintenance and reproduction of tenrecs at Tsimbazaza Zoo. (archived summary, tenrec husbandry).
http://tenrec.lima-city.de/pjs94.htm

World Association of Zoos and Aquariums (WAZA). Animal Welfare Standards and Guidelines.
https://www.waza.org/priorities/animal-welfare/

EAZA (European Association of Zoos and Aquaria). EAZA Standards for the Accommodation and Care of Animals in Zoos and Aquaria.
https://www.eaza.net