animal

architecture

arrive

beak

bill

bird

brood

builder

building

city

clay

construction

countryside

cup

delichon

europe

european

flight

flock

fly

ground

house

martin

material

migratory

moist

mud

muddy

nest

pellet

pick

plaster

pond

puddle

saliva

social

spit

street

swallow

synanthrope

town

urban

urbica

urbicum

village

water

wet

wildlife

work

worker