Discoid Roaches for Large Tarantulas: A Feeding Guide

Sizing Roaches to Tarantula Leg-Span

Large tarantulas—species with leg spans over 5 inches—can easily handle Medium and Large discoid roaches. The sizing rule for tarantulas is more forgiving than for smaller reptiles: a prey item should generally be no larger than about one-third of the tarantula's leg span, though tarantulas are often less finicky than you'd expect. A 7-inch-leg-span tarantula can manage a Large discoid roach (3/4 inch and up) without difficulty. Oversized prey is less of a concern with tarantulas than with frogs or geckos, because tarantulas use venom to subdue prey and have robust digestive systems built for processing large meals.

That said, offer roaches that are appropriately sized for the tarantula you're feeding. A Medium roach works well for most large-species tarantulas. Large roaches are fine for the biggest species—Goliaths, giant ornamental tarantulas, Brazilian wandering tarantulas. Err slightly on the undersized side if you're unsure, but don't feel you need to feed tiny roaches to a large tarantula. The roach should be substantial enough to register as a worthwhile meal for an animal with voracious feeding responses.

Live vs. Pre-Killed: When and Why

Most large tarantulas will take live roaches enthusiastically. A healthy tarantula, dropped a live discoid roach, will strike and inject venom without hesitation. Live feeding is naturalistic and engages the tarantula's predatory behavior. Discoid roaches, being non-aggressive and unable to climb, are low-risk prey—they won't turn the tables on the tarantula the way an aggressive cricket or other insect might.

However, some tarantulas are picky hunters, or they might refuse live prey during certain phases of their molt cycle. For those individuals, pre-killed or pre-stunned roaches can work. Gently stunning a roach by chilling it or striking it lightly—enough to immobilize it without crushing it—makes it easy prey for a tarantula that won't pursue. A pre-killed roach placed near the tarantula's web or directly in front of it will often be accepted, though some tarantulas refuse dead prey entirely. If your tarantula falls into the "picky eater" camp, live feeding is usually more reliable.

Feeding Frequency and Molt Timing

Large tarantulas, depending on species and sex, might feed once every 7 to 14 days, or even less frequently. An adult female might be fed once a week; an adult male, more sparingly. Juveniles and subadults with faster growth rates can be fed more frequently—every 3 to 5 days. Watch your individual tarantula's appetite and body condition. A full-bodied tarantula with a rounded abdomen is well-fed. A thin tarantula needs more food or more frequent meals.

Around a molt, feeding becomes complicated. Tarantulas typically stop eating 1 to 2 weeks before a molt (though some tarantulas eat until the molt begins). During the molt itself, offer no food—the tarantula is vulnerable, and its fangs are not deployed. After the molt, wait at least 2 weeks before offering food; the tarantula's exoskeleton needs time to harden and its venom to regenerate. Feeding too soon after a molt can result in a failed feeding response or harm to the tarantula.

If you're unsure whether your tarantula is approaching a molt, hold off on feeding. An extra week without food isn't harmful for a large tarantula; a misplaced feeding during molt preparation or molt itself can cause serious problems.

Roach Nutrition for Tarantulas

Discoid roaches have a protein content around 20%, fat around 7%, and calcium-to-phosphorus ratio of 0.77:1. For a tarantula, this is solid nutrition. Roaches are a complete diet for tarantulas—many keepers feed roaches exclusively and maintain healthy, long-lived animals. The nutritional profile is balanced enough to support growth, reproduction, and longevity. All Angles Creatures' discoid roaches arrive gut-loaded with organic produce, meaning they're packed with additional nutrients and hydration. A well-nourished roach becomes a well-nourished tarantula.

Varying prey types—mixing in crickets, grasshoppers, or other insects—doesn't hurt, but it's not necessary. If roaches are your preferred feeder, you can stick with them year-round without worrying about nutritional deficiency in your tarantula.

Managing Feeding in Communal Setups

Some keepers keep large tarantulas in communal or semi-communal setups, particularly with species known to coexist (like some Poecilotheria species). Feeding individual tarantulas in a shared enclosure requires care. The standard approach is to remove the fed tarantula to a separate container for feeding, then return it once the meal is consumed. This prevents competition, stress, and potential conflicts over prey.

If you're feeding a solitary tarantula in its permanent enclosure, place the roach directly in front of the tarantula or near its web. Most large tarantulas will feed immediately or within minutes. Remove any uneaten roach after 30 minutes to an hour to prevent it from dying and fouling the enclosure.

Recognizing a Picky Eater

Some tarantulas are just fussier than others. A picky eater might refuse live roaches but accept pre-killed or pre-stunned roaches. Others might only feed on specific prey types—if your tarantula was raised on crickets, it might take a while to accept roaches as food. Persistence helps. Offer a roach regularly (once a week), and eventually, most tarantulas will accept it. If your tarantula genuinely refuses roaches after multiple attempts, switch to a prey type it does accept, but there's no harm in trying occasionally.

Age can also affect pickiness. A young tarantula might feed aggressively, while an older, well-fed tarantula might eat less frequently or more selectively. Neither is cause for concern—just adjust your feeding schedule to match the individual's appetite and behavior.

Preventing Escape and Bite Risk

Discoid roaches don't fly, they can't climb smooth surfaces, and they're docile. The risk of a roach escaping and becoming a problem in your room is low, especially if you're feeding in a contained setup or removing the tarantula for feeding. If a roach does escape during feeding, it will hide in a dark corner—not aggressive, just seeking shelter. Discoid roaches pose no threat to human inhabitants, and they certainly won't harm a tarantula. For large tarantulas, roach feeding is one of the most stress-free and reliable feeding methods available.