Reed warblers are small in size and often move alone or in pairs. They like to perch on reed stems and small willow branches. They are sexually active, agile and cautious, and often hide in bushes or grass.
The call is a monotonous and dull 2-4 intermittent low call, sometimes imitating the singing of other birds. The call is a calm "churr" sound.
The food is mainly insects and their larvae. 87.5% of the food is insects, mainly locusts, accounting for 50%, followed by lepidoptera, ants, stink bugs and other pests. In addition, there are some weeds and leaves.
The breeding period is from May to July. The nest is built in reeds and bushes 0.5-1.5 meters above the water surface. The nest is cup-shaped, mainly made of dead grass stems and leaves, and padded with fine grass stems and horsetails. The size of the nest is: 6.5-9 cm in outer diameter, 4.5-5.5 cm in inner diameter, 5.0-7.0 cm in height, and 4-4.5 cm in depth. Each nest lays 3-6 eggs, which are blue-white or green-white with brown or gray spots. The size of the egg is 18.2 (16-20) mm × 13.6 (12.5-14) mm. Both parents incubate and raise the chicks together. The incubation period is 11-12 days, and the nesting period is 10-14 days.
Listed in the IUCN Red List of Threatened Species in 2017 ver 3.1 - Least Concern (LC).
