One of these bees is called the carder, and you may sometimes find its nest in a hollow in a bank. But it is not at all easy to see, for the bee covers over the hollow with a kind of roof, which is made of moss and lined with wax. And this looks so like the surrounding earth that even the sharpest eye may often pass it by. When this roof is finished, the bee makes a kind of tunnel, eight or ten inches long and about half an inch in diameter, to serve as an entrance; and this is built of moss and lined with wax in just the same way. On a warm sunny day in spring you may often see one of these bees flying up and down a grassy bank searching for a suitable burrow in which to build. Then you may be quite sure that she is a queen. For among bumblebees the drones and workers die early in the autumn, and only the queens live through the winter. Solitary bees are very common almost everywhere, and you may find their nests in all sorts of odd places. One kind of solitary bee, for example, builds in empty snail-shells, and another in small hollows like keyholes. A third gnaws out a burrow in the decaying trunk of an old tree, or in the timbers of a barn or house-porch and makes a number of thimble-shaped cells out of little semicircular bits of rose-leaf, which it cuts out with its scissor-like jaws. Haven't you noticed how often the leaves of rose-bushes are chipped round the edges, quite large pieces being frequently cut away? Well, that is the work of the leaf-cutter bee, as this insect is called, and very often not a single leaf on a bush is left untouched. But the commonest of all the solitary bees burrows into the ground. As you walk along the pathway through a meadow in spring, you may often see a round hole in the ground, just about large enough to admit an ordinary drawing-pencil. That is the entrance to the burrow of a solitary bee; and if you could follow the tunnel down into the ground you would find that it was about eight or ten inches deep, and that at the bottom were four round cells. In each of these cells the bee lays an egg. Then it fills the cells with flies, or spiders, and caterpillars, or beetles, for the little grubs to feed upon when they hatch out. For solitary bees do not nurse their little ones, as social bees do, and feed them several times a day. But at the same time the grubs are quite helpless, and cannot possibly go to look for food for themselves. So the mother bee has to store up sufficient to last them until the time comes for them to spin their cocoons and pass into the chrysalis state. These are only a few examples of a large number of interesting ways in which the solitary bees in various parts of the world provide for their young. WASPS