What do I feed my reptiles?

Feeding reptiles isn’t quite as simple as “open tub, insert food, job done.” In the wild, reptiles, amphibians, and invertebrates eat a surprisingly varied (and occasionally alarming) range of prey. In captivity, our job is to replicate that nutrition as closely as possible—without needing to source scorpions, baby birds, or anything that might fight back harder than expected.

Diet variety: nature is chaotic

In the wild, reptiles are opportunistic feeders. If it moves and they can overpower it, it’s probably on the menu.

You’ll find:
• Leopard geckos eating baby rodents
• Bearded dragons tackling scorpions and spiders
• Corn snakes wrestling lizards
• Monitor lizards raiding nests
• Large constrictors eating birds (and occasionally things that seem far too big for them)

Nature is not a polite buffet.
It’s more of a “grab what you can and hope it doesn’t bite back” situation.

In captivity, we can’t (and shouldn’t) fully replicate that chaos but offering variety where possible is key to good nutrition and enrichment.

Not all food is equal

Different prey items contain different levels of:
• Protein
• Fat
• Calcium
• Phosphorus
• Vitamins and minerals

For snakes and larger lizards that eat whole prey, this is important.

A varied diet of appropriately sized prey (mice, rats, chicks, etc.) provides:
• Muscle (protein)
• Organs (vitamins and minerals)
• Bones (calcium)
• Skin/fur (fibre and roughage)

In most cases, whole prey diets don’t require heavy supplementation, because they are nutritionally complete.

Think of it as:
A whole animal = a complete meal.

That said, occasional supplementation (like lightly dusting prey once a month) can help cover any trace deficiencies—basically the reptile equivalent of a multivitamin.

Insects: small but nutritionally complicated

For insect-eating reptiles (like geckos and bearded dragons), things get a bit trickier.

Insects vary massively in nutritional quality. Some are excellent staples; others are basically junk food with legs.

For example:
• Locusts and dubia roaches = good staples
• Crickets = decent but not amazing
• Mealworms = okay in moderation
• Waxworms = reptile dessert (high fat, low nutrition)

If your reptile could choose freely, it would probably eat only the equivalent of cheeseburgers and cake.

Which is exactly why you’re in charge.

The calcium problem (and why dusting matters)

Here’s where things get important.

Most insects and plant matter are high in phosphorus but low in calcium. This creates an imbalance in the calcium-to-phosphorus ratio.

Reptiles need roughly:

If there isn’t enough calcium available, the reptile’s body will start pulling calcium from its own bones.

Which is exactly as bad as it sounds.

This can lead to:
• Metabolic Bone Disease (MBD)
• Weak or deformed bones
• Poor growth
• Muscle issues

To prevent this, live insects and greens should be dusted with calcium powder regularly.

Especially for:
• Juveniles (fast growth)
• Gravid females (egg production)

In short:
If your reptile eats insects, calcium dusting is not optional.

Vitamin and mineral supplements

Back in the 1960s and 70s, reptiles (especially tortoises) were often kept with little to no dietary supplementation.

The result?
Extremely high mortality rates.

We’ve learned a lot since then.

In captivity, reptiles can miss out on trace vitamins and minerals that they would naturally obtain in the wild. That’s where supplementation comes in.

Key vitamins

• Vitamin A – eyesight, immune system, organ health
• Vitamin B – metabolism and nervous system
• Vitamin C – tissue health and repair
• Vitamin E – cell protection and vitamin absorption

Important minerals

• Iodine – thyroid function
• Calcium – bones, muscles, shell growth
• Zinc & magnesium – metabolism and enzyme function
• Copper & manganese – development and immune support

Deficiencies can cause:
• Poor growth
• Weak immune systems
• Developmental problems

The big one: Vitamin D3

Vitamin D3 is absolutely critical for reptiles because it allows them to use calcium properly.

Reptiles can get D3 in two ways:

1. Supplements
2. Producing it themselves using UV light

The best method?
Let them produce it naturally using UVB lighting.

This process (called thermal isomerisation) allows reptiles to convert UV exposure into usable vitamin D3.

Translation:
No UV = no D3 = no calcium use = big problems.

Feeding made simple

If all of this sounds complicated, here’s the simplified version:

For snakes and large carnivores:

• Feed whole prey
• Offer size-appropriate variety
• Supplement occasionally (lightly)

For insect-eaters:

• Use a mix of feeder insects
• Gut-load insects (feed them well before feeding them off)
• Dust with calcium regularly
• Add vitamin supplements weekly

For herbivores:

• Provide a wide variety of leafy greens and weeds
• Supplement calcium
• Avoid high-sugar fruits

Final thoughts

There is a lot of conflicting advice out there about reptile diets, and it can get overwhelming quickly.

But the core principles are simple:
• Variety is good
• Balance is essential
• Supplements fill the gaps
• UV lighting is critical

A well-fed reptile is:
• Active
• Growing properly
• Shedding well
• Maintaining good body condition

And, perhaps most importantly:
Not staring at you like you’ve personally failed it at dinner time.

Because let’s be honest—no matter how carefully you plan their diet, reptiles still have a special talent for acting like they’ve never been fed in their entire life.

You Are What You Eat: The Truth Of Gut Loading

Rats vs. Mice: Which Is the Best Feeder for Your Snake? (A Nutritional Debate with Teeth… and Tails)

Crickets vs. Locusts: Which Is the Best Feeder Insect for Your Reptile? (A Nutritional Showdown)

For some tips and tricks check out our YouTube channel we have some fun videos with our animals and herptile care!