Yes - that is what happened to a house martin's nest on our house. The sparrows took over and hatched two babies. Sadly though the nest collapsed and it and the babies ended up on the lawn. So disaster.
Hedge sparrows are properly called dunnocks and they are not actually sparrows at all. They build their nests in dense shrubbery and hedgerows (see Sources and related links, below).
In a Barn.
Nests up in trees like any other birds... outside.
Yes, both bluebirds and sparrows are cavity nesters. This means they both use birdhouses to make nests in. Sparrows are very fierce and often when fighting with bluebirds they kill its babies or break their eggs.
No, the smallest frog is still bigger than a swallow's mouth.
Sparrow's are common on school grounds because they reuse old nests that could have been by the school grounds. Some sparrows are attracted to octopuses and feed on cats. Sparrows can sometimes eat cans as well.
Mocking birds do not build nests. They lay their eggs in other bird's nests.
the nests? they're made up of mostly mud
Swallows are on average 20 g heavier then sparrows, but weight varies depending on species.
the swallow tattoo is a traditional naval tattoo. many sailors would get swallows/sparrows on their chest. one swallow would represent 5000 nautical miles traveled and a second would be 5000 more. they also were known to symbolize the end of a journey. mainly because sparrows were the first sign of land and would let the sailors know they are almost home.
Basically, any bird that also nests in cavities. These often include bluebirds, other swallows, wrens, and house sparrows.
House sparrows and starlings often compete with bluebirds for places to build nests.