What colony do you need to feed your animals?

How we calculate

• Need (feeders / week) = sum of your animals × their ration: adult leopard gecko 15, juvenile 35, adult bearded dragon 30, juvenile 250, chameleon 25, crested gecko 6, tarantula or scorpion 2, mantis 7, ant colony 10, plus your “other feeders”.
• Heat factor (roaches and crickets) = 0.1 below 24 °C (the colony stalls), 0.4 from 24 to 27 °C, 0.7 from 27 to 29 °C, 1 from 29 to 34 °C, 0.7 above. Mealworms: 0.2 below 20 °C, 0.5 from 20 to 23 °C, 0.8 from 23 to 25 °C, 1 from 25 to 30 °C, 0.7 above.
• Females = need ÷ (harvestable young per female per week × factor), rounded up: 2.2 for dubia, 5 for red runner, 12 for crickets. Minimum 20, 20 or 30 females. Males = females ÷ 5 (dubia) or ÷ 3 (red runner, cricket), rounded up, minimum 5, 7 or 10.
• First harvest = 4 months (dubia), 3 months (red runner) or 2 months (cricket) ÷ √factor, rounded to the half month. Starting with 100 nymphs, self-sufficient in 9, 6 or 3 months ÷ √factor.
• Bins: egg crates = adults × 20 (dubia) or × 30 (red runner) ÷ 150, rounded up, at least 2, and 1 bin of 60 × 40 × 30 cm per 12 crates. Crickets: need × 8 ÷ 400 bins of 20–30 L, at least 2.
• Mealworms = need ÷ (300 × factor) trays of 60 × 40 cm, rounded up, at least 1, with 500 adult beetles (or 100 g of worms) per tray. First harvest = 3 months ÷ factor, rounded to the half month.

Example

2 adult bearded dragons, dubia colony at 28 °C. Need = 2 × 30 = 60 feeders / week. Heat factor 0.7, so 60 ÷ (2.2 × 0.7) = 38.96, i.e. 39 females + 8 males (47 adults to start). Egg crates = 47 × 20 ÷ 150 = 6.3, so 7 crates in 1 bin of 60 × 40 × 30 cm. First harvest: 4 ÷ √0.7 = 4.8, so ≈ 5 months.

Sources: common keeping practice. These are guidelines: real output depends on heat, food and humidity.

Frequently asked questions

How many dubia roaches to feed a leopard gecko?

An adult leopard gecko eats about 15 feeders a week. For 2 geckos at 30 °C, the calculator suggests the stable minimum: 20 females and 5 males.

Why does temperature matter so much?

Roaches breed at full speed between 29 and 34 °C. Between 24 and 27 °C they produce 2.5 times less, and below 24 °C the colony almost stops.

How long until the first harvest?

About 4 months for dubia, 3 for red runners and 2 for crickets at 30 °C, longer if it is colder.

How many mealworms per tray?

A 60 × 40 cm tray gives about 300 worms a week at a good temperature. Start with 500 adult beetles per tray.