Best Feeder Insects for Pacman Frogs, Ranked by a Keeper
Pacman frogs (Ceratophrys) are basically a mouth with legs. They're ambush predators with enormous gapes and legendary appetites, built to sit half-buried in the substrate and explode on anything that wanders within range. That makes them one of the easiest amphibians to feed — they'll take almost anything — and one of the easiest to feed wrong, because they have no off switch. With a Pacman frog, the whole game is choosing nutritious, lean feeders and resisting the urge to feed too often.
Here's how the common feeders rank for Pacman frogs, and then the feeding-frequency rule that matters more than any single item on the list.
The ranking
1. Large discoid roaches — the staple
~20% protein, ~7% fat. This is the ideal Pacman staple. Large roaches walk slowly across the substrate, which triggers the explosive ambush strike these frogs are wired for, and at only about 7% fat they're lean enough to feed regularly without contributing to the obesity Pacmans slide into so easily. Offer 3–5 per feeding for an adult. Discoid roaches are also low-chitin and easy to digest, which makes them gentle on a frog that swallows prey whole. For a clean, consistent source, All Angles Creatures stocks large discoid roaches sized right for adult Pacmans.
2. Silkworms — the leanest option
~1% fat, no chitin. Silkworms are the leanest feeder on this list, which makes them perfect for obesity-prone frogs. Their soft, chitin-free bodies pass through the digestive system smoothly, and their slow crawl triggers the strike beautifully. Use medium-to-large silkworms, 3–5 per feeding. A great staple to rotate against discoid roaches.
3. Earthworms / nightcrawlers — natural prey
Earthworms are genuine natural Pacman food — high moisture, good protein, and taken eagerly. Canadian nightcrawlers are the right size for an adult. They add excellent variety alongside insect feeders and need no special prep beyond keeping them clean.
4. Hornworms — the hydration treat
~85% moisture. Hornworms are mostly water, which makes them a great hydration treat rather than a staple — they can't carry a diet on their own. Their bright color and large size trigger strong strikes, so Pacmans take them eagerly. Offer 1–2 per feeding, 1–2 times a week.
5. Black soldier fly larvae — the calcium card
~9,000+ mg/kg calcium. BSFL are the one feeder that's naturally calcium-rich, so they don't need dusting. Pacmans accept them readily — the slow wriggle triggers the ambush instinct. Offer 5–15 per feeding, 1–2 times a week as a calcium supplement to the rest of the diet.
Sizing feeders and feeding safely
Pacman frogs have enormous mouths, which makes it tempting to throw oversized prey at them — but the same impaction and choking rules apply as with any frog. A good guideline is to keep feeders no wider than the space between the frog's eyes. A Pacman can cram down something bigger, but "can" and "should" aren't the same thing, and oversized prey is a real risk.
There's also a substrate problem unique to ambush feeders: because Pacmans strike explosively at prey moving across the ground, they routinely grab a mouthful of substrate along with the feeder. On loose, swallowable substrate (small gravel, fine bark) this leads to impaction over time. Two fixes work well — keep them on a safe substrate like coconut fiber that won't impact if a little is swallowed, or feed with tongs so the prey never touches the ground. Tong-feeding also lets you control exactly how much each frog eats, which matters a lot for a species this prone to obesity.
Gut-loading and supplements
The nutrition of your feeder is really the nutrition of whatever the feeder ate, so gut-load your insects with quality produce and chow for 24–48 hours before feeding off — well-fed roaches and silkworms deliver far more to your frog than starved ones. Then dust with calcium as described above. A simple working schedule for most Pacmans: plain calcium on most feedings, and a calcium-plus-D3 or multivitamin product a couple of times a month. BSFL, being naturally calcium-rich, are the one feeder you can offer undusted.
Feeding frequency — the #1 Pacman mistake
This is the part that actually keeps a Pacman frog healthy, and it's counterintuitive: Pacman frogs should not eat every day. They're ambush predators adapted to intermittent feeding; in the wild they may go days or even weeks between meals. In captivity:
- Juveniles: every 2–3 days
- Adults: every 5–7 days
Overfeeding is the single most common Pacman care mistake. These frogs will eat everything you put in front of them and become grotesquely obese, which shortens their lives and stresses their organs. The mantra to keep in your head: a slightly hungry Pacman is a healthy Pacman. Let body condition — not the frog's bottomless enthusiasm — set the schedule.
What not to feed
- Waxworms as a staple — about 25% fat. Fine as a rare treat, disastrous as a regular food for an obesity-prone frog.
- Daily pinky mice — far too much fat. Occasional only, no more than 1–2 times a month, and many keepers skip them entirely.
- Wild-caught insects — risk of pesticides and parasites you can't see.
Don't forget calcium
Nearly every feeder insect is phosphorus-heavy with poor calcium, so dust insect feeders with a calcium supplement to head off metabolic bone disease. The exception is BSFL, which are naturally calcium-rich and don't need dusting — that's exactly what makes them so useful in the rotation. For the clinical background on amphibian nutrition and the deficiency diseases poor diets cause, the MSD/Merck Veterinary Manual's amphibian section is a reliable non-commercial reference.
Juveniles vs. adults
The diet shifts as a Pacman grows. Juveniles are growing fast and eat more often (every 2–3 days), taking smaller versions of the same feeders — small discoid nymphs, small silkworms, and appropriately sized crickets — always dusted with calcium to support that rapid bone growth. Adults slow right down to a meal every 5–7 days and move onto the larger staples. The temptation with a fast-growing juvenile is to "power-feed" it to size; resist it. Growing a Pacman too fast stresses the animal, and obesity that starts young follows the frog for life. Steady, calcium-supported growth beats a forced sprint every time.
A note on hydration
Pacman frogs don't drink from a bowl — they absorb water through their skin, mostly via a permeable patch on the belly and thighs, while sitting on damp substrate or in shallow water. That's another reason the high-moisture feeders matter: an earthworm or a hornworm delivers real water content along with nutrition. Keep the substrate appropriately moist and provide a shallow, clean, dechlorinated water source, and your frog stays hydrated between meals.
Reading your frog's body condition
Because overfeeding is the central risk, learning to read a Pacman's body condition is the most useful skill you can develop. A healthy Pacman is round but not bloated — it should look like a well-stuffed cushion, with the body wider than tall when sitting and no dramatic bulges. An obese Pacman develops a swollen, taut appearance, sometimes with fat deposits visible, and may struggle to bury itself or right itself. An underweight frog (rare in captivity) shows visible hip bones and a sunken look. Let the frog's shape, not its appetite, drive how often you feed — and when in doubt, wait another day.
How to offer prey
Pacmans hunt by sitting motionless and ambushing movement, so they feed best when the prey moves. Drop a feeder a few inches in front of the frog, or wiggle it on feeding tongs, and the strike is usually instant and dramatic. Tong-feeding is my default: it keeps substrate out of the frog's mouth, lets me count exactly what each animal eats, and avoids feeders burrowing into the substrate where the frog can't find them. If a frog ignores food, it's often simply not hungry yet (remember the 5–7 day adult schedule) — remove the feeder and try again in a day or two rather than leaving live insects to crawl on the frog.
Why variety beats any single feeder
It's tempting to find the "best" feeder and use only that, but no single insect is nutritionally complete. Discoid roaches and silkworms make excellent lean staples, but rotating in earthworms (moisture and natural prey), hornworms (hydration), and BSFL (calcium) gives your frog a fuller nutritional profile than any one of them alone. A varied diet, properly supplemented and correctly portioned, is what keeps a Pacman frog healthy for its full 10-plus-year potential lifespan.
The short version
Build the diet around large discoid roaches and silkworms as lean staples, rotate in earthworms for variety, use hornworms as a hydration treat and BSFL as a calcium boost, dust your insects with calcium, and — above all — feed adults only every 5–7 days. Get the frequency right and a Pacman frog is one of the most low-maintenance, characterful amphibians you can keep.
Setting up the rest of the enclosure? See my Pacman frog habitat care guide, or browse the full exotic animal care library for more on each of these feeders.