Tamanduas have tapered heads with a long, tubular snout, small eyes, and protruding ears. Their tapered mouths house a tongue reaching upwards of 40 cm (16 in) in length. The tail is hairless and pink in color, marked with an irregular pattern of black blotches. The forefeet possess four clawed digits, the third digit bearing the largest claw, while the hind feet have five digits.Their fur is thick, bristly, yellowish-white to fawn in color, often with a broad black lateral band, covering nearly the whole of the side of their bodies. Northern tamanduas are marked with a black V on their backs and a "vest" over their torso; southern tamanduas vary in appearance across their range, from a vested pattern like northern tamandua, to only partially vested, to entirely light- or dark-colored.

Tamanduas are nocturnal, active at night and secreting away in hollow tree trunks and burrows abandoned by other animals during daylight hours. They can spend more than half of their time in the treetops, as much as 64%, where they forage for arboreal ants and termites. Tamanduas move rather awkwardly on the ground and are incapable of galloping like their relative, the giant anteater. Tamanduas walk on the sides of their clenched forefeet to avoid injuring their palms with their sharp claws.