Katydids vs. Discoid Roaches for Blue Tongue Skinks: Which Feeder Wins?
Blue tongue skinks are omnivores with big appetites and broad tastes, which is good news — they'll eat almost any well-chosen feeder. The katydid-versus-discoid question comes up because both are soft-ish, protein-rich insects that suit a skink, but they're very different to actually live with. Having fed roaches as a staple for years, I'll give you the honest verdict up front: discoid roaches are the better staple, katydids are a nice occasional treat — and the deciding factors are reliability and handling more than nutrition.
What a blue tongue skink needs
Blue tongues are true omnivores. A working adult diet is roughly half animal protein and half plant matter — dark leafy greens (collard, mustard, turnip), vegetables like squash and bell pepper, and fruit only sparingly because of the sugar. Juveniles lean more heavily on protein for growth. Whatever insect you choose fills the protein slot, and it must be dusted with calcium to protect against metabolic bone disease, which the Merck Veterinary Manual's reptile nutrition overview explains is one of the most common preventable problems in captive reptiles.
That dusting requirement applies to both feeders here, which is the first myth to clear away.
The calcium myth, cleared up
You'll see claims that discoids have a "favorable" calcium-to-phosphorus ratio and that one feeder beats the other on calcium. The truth: katydids and discoid roaches are both phosphorus-heavy. Like crickets, dubia, mealworms, and nearly every other feeder insect, neither delivers the calcium-to-phosphorus balance a skink needs on its own. So calcium is not a tiebreaker — you gut-load and dust either one. (The genuine high-calcium feeder exception is black soldier fly larvae, not katydids or discoids.) Decide on the factors that actually differ.
Nutrition: roughly comparable
Both are solid protein feeders. Katydids are lean, with a high moisture content that adds some hydration. Discoids are high-protein with low chitin, which makes them notably easy for a skink to digest — a real plus for juveniles and any skink with a sensitive gut. You'll find wildly varying protein percentages quoted for both (dry-weight figures inflate the numbers); the practical takeaway is that on nutrition alone, it's close to a wash. Both are good protein. Both need dusting. Neither is a knockout winner here.
Where they actually differ
Availability and reliability
This is the big one. Discoid roaches are consistently available year-round, sold in graded sizes, and easy to breed at home for a self-renewing supply. Katydids are patchy — not widely captive-bred, often seasonal, sometimes only available wild-caught. For a staple you feed every week, a feeder you can't reliably get is disqualifying. Discoids win on supply, decisively.
Sourcing safety
Because katydids are often wild-caught, they carry more risk: pesticide exposure, parasites, and the ecological downside of over-collecting. Discoids in the feeder trade are farm-raised on clean diets in controlled conditions. If you do feed katydids, insist on captive-bred — never grab them from the yard.
Handling and containment
Discoids are easy: slow-moving, can't climb smooth surfaces, can't really fly, so they stay in a feeding dish or bin. Katydids are jumpy and prone to leaping away during feeding or cleaning, and they need a more involved enclosure with live plants and fresh greens if you hold them for any length of time. For a busy keeper, discoids are far less hassle.
Cost over time
Per insect, katydids tend to run more expensive, especially off-season, and since they don't breed readily in captivity you keep rebuying. Discoids are cheaper in bulk and effectively free once a home colony is running. Long-term, discoids are the budget pick.
The head-to-head
| Factor | Discoid roach | Katydid |
|---|---|---|
| Protein | High | High |
| Calcium:phosphorus | Phosphorus-heavy (dust it) | Phosphorus-heavy (dust it) |
| Digestibility | Very good (low chitin) | Good, hard exoskeleton on larger ones |
| Hydration | Moderate | Higher (more moisture) |
| Availability | Year-round, graded sizes | Patchy, often seasonal/wild |
| Sourcing safety | Farm-raised, controlled | Often wild-caught (pesticide/parasite risk) |
| Handling | Easy, no climbing/flying | Jumpy, escape-prone |
| Cost over time | Low (breeds at home) | Higher (rebuy) |
| Best role | Staple | Occasional treat |
My recommendation
Build the protein side of your blue tongue's diet on a discoid roach staple — reliable, easy, digestible, affordable, and contained. Use katydids as an occasional enrichment treat when you can get clean captive-bred ones; their movement triggers the skink's hunt drive and adds dietary variety, which is genuinely valuable. The wild blue tongue eats a varied diet, so rotating feeders on a roach base is closer to natural than feeding any single insect.
Practical feeding notes that apply to both:
- Size to the skink — no feeder wider than the space between its eyes.
- Gut-load 24 hours ahead, then dust with calcium (with D3 on the schedule your setup needs).
- Use feeding tongs, and remove anything uneaten so it doesn't stress the skink or foul the enclosure.
- Offer the insect portion a couple of times a week alongside the greens and vegetables.
When you're setting up that staple, All Angles Creatures stocks discoid roaches in sizes from small nymphs to adults, so you can match the feeder to your skink's age and size.
How much and how often
Getting the amount right matters as much as the choice of feeder. A few practical guidelines I use for blue tongues:
- Juveniles are growing fast and lean more on protein — offer appropriately sized feeders more frequently (often every day or every other day), as many as the skink will take in a short window, alongside finely chopped greens.
- Adults shift toward more plant matter. A protein meal a couple of times a week is typical, with daily access to greens and vegetables and only occasional fruit.
- Portion to the animal, not the bag. Stop when the skink loses interest; uneaten feeders should be removed so they don't stress the animal or foul the enclosure.
- Watch body condition. A blue tongue carrying too much weight needs leaner, less frequent protein; a thin one needs more. Adjust over weeks, not days.
Whichever feeder you offer, gut-load it for about 24 hours beforehand and dust it with calcium (with D3 on the schedule your UVB setup calls for). That two-step habit does more for your skink's long-term bone health than the katydid-versus-discoid decision itself.
If you can only get one
Plenty of keepers can't reliably source katydids at all, and that's fine — a dusted, varied diet built on discoid roaches plus greens and vegetables is a complete, healthy diet for a blue tongue skink with no katydid required. Katydids are a "nice to have" for variety and enrichment, not a nutritional necessity. If they're available and clean, use them as one of several rotating treats (alongside other feeders); if they're not, don't lose sleep over it. The reverse isn't true: a katydid-only diet would be unreliable and harder to balance, which is another reason the roach is the sensible foundation.
Bottom line
Nutritionally it's close and both need dusting, so don't agonize over a "calcium ratio." Decide on what actually differs: discoids are the reliable, easy, affordable staple, and katydids are a fun occasional treat when you can source them safely. Feed a dusted discoid base, rotate in variety, and your blue tongue eats the way it should.
Comparing more options for your skink? The full feeder insect library covers the alternatives, and my discoid roach care and breeding playbook shows how to keep that staple colony running.