No. The nest may not really be abandoned even though it looks like it.
Unless you're talking about domestic fowl like chickens, then, yes, you should remove the chick to a location that it can find food in.
Yes, then clean the box.
If there is a nest that is abandoned you should destroy it.
a nest
in a nest
yes
If the eggs have been left untended for more than 24 hours they most likely are or will die.
It is illegal to destroy a mockingbird nest that is active or has eggs or nestlings in it, as they are protected under the Migratory Bird Treaty Act. You may only remove a mockingbird nest if it is abandoned and no longer in use.
If one baby robin remains in the nest while its siblings have fledged, it may indicate that it is not yet ready to leave due to being less developed or weaker. The parent robins typically continue to care for the remaining chick, providing food and protection until it is strong enough to fledge. If the chick is healthy, it will eventually leave the nest when it is ready. However, if it appears to be abandoned or struggling, it may require human intervention to ensure its survival.
A chick when a nestling or an eaglet once it can leave the nest.
No, you should leave the nest alone. Wild birds are very skittish around humans, treating humans as predators, and may abandon the nest if the scent of a human becomes too close. This would result in any eggs already laid in the nest also being abandoned and dying. The birds that built the nest either expect the nest to be protected from the rain or are adapted to sitting out the rain on the nest.
Remove and discard immediately.
You should call pest control or ask a professional.