What Do Tarantulas Eat Unlocking The Secrets Of Their Carnivorous Diet

Feeding Tarantulas: The Actual Process

Tarantulas are obligate carnivores, which means their entire nutritional profile depends on live or freshly killed invertebrate prey. There is no plant matter in their diet, no algae pastes, and no substitutes that come close to replicating whole prey. This isn't a preference issue. Their digestive systems produce enzymes calibrated specifically for processing chitin and animal protein. Feed them anything else and you will watch their health degrade over months with no obvious warning until something breaks. The prey spectrum is narrow but not as rigid as some keepers believe. In the wild, a mature male Chilean rose tarantula (Grammostola rosea) will take crickets, roaches, mealworms, and occasionally small frogs or mice depending on size and opportunity. Captive specimens follow the same pattern. The main variables are prey size, frequency, and nutritional supplementation. Everything else is secondary.

What Do Tarantulas Eat Unlocking The Secrets Of Their Carnivorous Diet

Here is what most beginners get wrong about feeding tarantulas. They treat it like a chore checklist instead of a monitoring tool. Every feeding is your opportunity to assess molting status, body condition, parasitism signs, and digestion efficiency. If you are just dropping prey in and walking away, you are missing data you will need later when something goes wrong. Prey size should never exceed the tarantula's carapace width by more than twenty percent. This is a hard rule across most species. A Gooty ornamental (Poecilotheria metallica) that has a three-inch carapace should not be attempted on a full-grown rat. Even if the tarantula kills it, the metabolic cost of subduing and processing oversized prey can cause fatal stress or regurgitation. I learned this the hard way with a young Avicularia avicularis. I offered a superworm that was roughly the same length as the spider's leg span. The tarantula impaled it but couldn't manipulate it properly. The prey burrowed into the substrate and died. The carcass decomposed inside the enclosure and introduced a mite infestation that took six weeks and repeated heat treatments to eliminate. From that point forward, I cut all prey length in half as a safety margin regardless of species. Feeding frequency varies dramatically by life stage. Hatchlings and spinlings feed every three to five days because their metabolic rate is high and their stomach capacity is tiny. Juveniles settle into a two-to-three day rhythm. Adult females on the other hand can go weeks or even months between meals without any measurable health decline. This is where the common advice of "feed once a week" falls apart because it assumes all tarantulas are the same size and life stage, which they absolutely are not.

Nutritional supplementation matters more than people realize. Crickets and mealworms alone create calcium deficiencies over time. I dust prey with a calcium carbonate supplement containing trace minerals every second feeding. The ratio is roughly one gram of powder per twenty grams of prey mass. You do not need to coat it heavily. A light dusting is sufficient. I also rotate prey types to vary the amino acid profile. Roaches provide different lipid profiles than crickets, and dubia roaches have a harder exoskeleton that requires more grinding effort from the tarantula, which actually strengthens the chelicerae over time. There is a significant downside to relying on feeder insects exclusively. Their nutritional content fluctuates based on what they were fed before being sold to you. A batch of crickets that spent three days on dry cereal flakes will have a completely different calcium-to-phosphorus ratio than crickets raised on commercial gut-load formulas. If you are serious about long-term husbandry, you either gut-load your own prey or supplement consistently. I gut-load crickets and roaches with chopped sweet potatoes, carrots, and calcium-rich greens for forty-eight hours before offering them to the tarantulas. It adds about ten minutes to my weekly routine and eliminates the guesswork around insect nutrition. Another overlooked factor is the molting cycle. Never feed a tarantula that is approaching a molt. The telltale signs are a darkening abdomen, reduced activity, and sometimes a distinct purple or grey sheen on the carapace. Feeding during this window risks the tarantula dropping its prey mid-digestion, which leads to prey escaping and dying in the enclosure, or worse, the tarantula attempting to feed with its fangs exposed while its new exoskeleton is still soft. I stop all feeding two weeks before a predicted molt and resume only after the tarantula has been actively hunting for at least seventy-two hours post-molt. This timing prevents the vast majority of feeding-related injuries I see in rescue cases.

If you want to skip the feeding process entirely for a period, healthy adult females can tolerate fasting for up to six months without irreversible damage. Males are different. Once they mature and begin their wandering phase in search of mates, their metabolic demands spike and they can starve within three to four weeks if prey is unavailable. This is why adult male tarantulas often die shortly after their final molt even in well-maintained enclosures. It is not old age. It is an energy bottleneck created by the transition from a sedentary juvenile phase to an active adult phase with no proportional increase in feeding opportunities. The prey species you select should match the hunting strategy of your tarantula. Jumping spiders take bolt-and-grab prey like flightless fruit flies and pinhead crickets. Myogenic hunters like theraphosids and tarantulas use a sit-and-wait approach and prefer larger, slower-moving prey they can engulf. Mismatching prey type to hunting style results in wasted feedings and stressed animals. A phoniatric tarantula will not pursue a fast-running beetle the way a ground-dwelling huntsman spider would. Offer it something that triggers its strike response, which usually means prey that moves slowly enough to be intercepted but large enough to require wrapping in silk before consumption.