This non-migratory bird, like most babblers, has small rounded wings and a weak flight and is typically seen in groups calling and foraging. Although it has a distinct call and prefers more vegetated habitats, it is often confused with the jungle babbler, whose range overlaps in parts of southern India. T. leucocephala, also known as a white-headed babbler, is also confused with it.

The upper parts of these birds are grey-brown, with a pale buff belly and a grey throat and breast with some mottling. Greys are used on the head and nape. T. a. taprobanus is a drab light grey in Sri Lanka. The crown and nape of the southern Indian nominate race are whitish, with a darker mantle. The tail has a long dark tip and the rump is paler. The birds in India's extreme south are very similar to the Sri Lankan subspecies, with the exception that the crown and back are greyer. The eye is a pale bluish-white color. The throat and breasts of the Indian type are more extensively streaked. Although the jungle babbler, Turdoides striatus, does not occur on the island, the Sri Lankan subspecies resembles it.

There are seven distinct vocalizations in this genus, and its call is higher-pitched than the jungle babbler's. The calls of the forest babbler are harsher and more nasal.

In the past, the taxonomy of this species was muddled, and it was mistaken for the sympatric jungle babbler and the Sri Lankan Orange-billed babbler.

The distribution of this species is patchy in southern India and Sri Lanka. Andhra Pradesh, south of the Godavari River, and Karnataka, south of Belgaum, into Tamil Nadu, are home to the nominate subspecies. It prefers lower altitudes and drier conditions than the jungle babbler, but it does sometimes coexist with it. The Sri Lankan subspecies lives in the lowlands and hills up to 1500 meters above sea level, avoiding dense forest. It is a popular garden bird that can be found in both urban and suburban settings.

The yellow-billed babbler is found in flocks of seven to ten individuals. The constant chattering, squeaking, and chirping produced by its members can generally be detected from a distance, indicating the presence of a flock. Occasionally, all of the participants begin chatting loudly enough to irritate the human ear. While the rest of the flock forages on or near the ground, one member sometimes perches high and serves as a sentinel. They consume insects mostly, but also berries, nectar, and human food scraps. Calotes versicolor lizards and whip-scorpions have been known to be taken. They do not fly long distances; the longest non-stop flight was around 180 meters, and they normally gain height by climbing a tree or tall shrub before taking it to the air. Near these babblers, black drongos, rufous treepies, and Indian palm squirrels have often seen foraging.

Birds start foraging about 6:00 a.m. before the sun rises. During the hot hours of the day, from 1:30 PM to 4:30 PM, they are relatively inactive. Around 7:00 p.m., they gather in groups and groom themselves before heading to roost. A group of birds roosts next to each other, with some juveniles squeezing themselves into the center. The sentinel bird makes wing fluttering and jumping calls while foraging. Allopreening is a common practice, particularly in the winter, when members rely on one another for food. Yellow-billed Curlew Bathing is a favorite pastime for babblers, and they may frequent birdbaths in their general territory in the late afternoon or evening. These birds have been seen visiting bird baths after sunset, about 6:30 p.m. when darkness is starting to fall.

They are generally uneasy when humans are close by, but they are always brave.

The species' nests can be seen all year, but the peak breeding season is just before the Southwest Monsoon arrives. It makes its nest in a pine, tucked away among the foliage. The majority of nests are located below four meters in height. A small cup is set in the fork of a branch as the nest. The average clutch size is two to four turquoise blue eggs, while birds in Sri Lanka's hills have been known to lay up to five. After 14 to 16 days, the eggs hatch. Instead of sitting on the chicks, a brooding parent bird will always stand on the surface of the nest. The pied cuckoo (Clamator jacobinus) is known to parasitize broods in both India and Sri Lanka. A brood parasite has been identified in the common hawk-cuckoo. Jungle babblers have been seen feeding the yellow-billed babbler chicks in an unusual situation. Insects and the occasional lizard are the primary sources of nutrition for the chicks. The parents, like most perching birds, are responsible for nest sanitation, eliminating the young's fecal sacs by swallowing them. Helpers have been observed assisting the parents in the construction of the nest as well as the feeding of the chicks.