At this time of year you will notice large fat bumble bees about the garden looking for a place to nest and raise their young. Having mated in the fall and spent the winter burrowed underground the queen bumble bee is now ready to produce the next generation of female worker bees.
When searching for a nest the queen will use both sight and smell. She flies low over the ground in a zig-zag pattern that is quite distinctive. Bumblebees tend to nest in relatively undisturbed areas such as shaded corners or in trees or long grass. The resulting nests are much smaller than honeybee hives and easily go unnoticed in the garden. They will however find their way under sheds and into eaves but rarely cause any problems to humans.