The reason why some birds won't stop chirping at night is because they are nocturnal and actively vocalize during the night.
Birds that are nocturnal will chirp at night due to mating season or defending their territory or as a way of communicating with other nocturnal birds.
Most bird species are diurnal and are active during the day and sleep at night so the birds you do hear at night are often the nocturnal birds.
If you hear a bird chirp at night it means that the bird is a nocturnal species of bird or they are communicating with other birds, searching for a mate or establishing their territory.
Some birds may chirp at night when they're disoriented by artificial light.
The reason birds chirp at 5am is because it's the birds way to attract mates, communicate with other birds in their flock and to establish their territory.
The morning air allows the birds chirps and sounds including songs to carry further without interference from background noise.
Birds chirping in the morning is especially prevalent and common during breeding seasons.
The early morning also has the least ambient noise and maximizes the distance that a bird's song can travel.
When birds are loud in the morning it means that the birds are participating in a dawn chorus which is where male birds will sing loudly in the morning to attract mates or communicate with other birds or defend their territory.
The birds take advantage of the quiet morning air which carries the birds song further with less background noise and is most prominent during the birds breeding season.
The birds that start singing first in the morning are song thrushes, robins and blackbirds.
Song thrushes, robins and blackbirds start their singing when it's still dark and the air is cool.
Birds will sing in the morning to defend territory, attract mates and to raise their young.
Male birds will often sing in the morning to show that they are healthy, fit and have a good territory with lots of food available.
Most birds will start singing first in the morning or in the morning from March to July and the peak of the birds singing is in May and June.
The dawn singing chorus from birds is the loudest and the clearest during the spring breeding season.
Some other birds will also join in with the singing at dawn.
These birds that will also join in with the birds singing in the morning or at dawn include.
Wrens.
Warblers like Willow Warblers, Blackcaps, Chiffchaffs.
The song thrush bird is also known for it's many short fluty phrases which is repeated a few times after a pause.
The house sparrow is also know for it's chirp in the morning.