The _digging wasp_ (Figs. 160 and 161) supplies its larva with caterpillars and closes the hole, sometimes using a stone as pounding tool. Among the few other uses of tools among lower animals are the elephant’s use of a branch for a fly brush, and the ape’s use of a walking stick. This wasp digs with fore feet like a dog and kicks the dirt out of the way with its hind feet. Are the wings of bees and wasps more closely or less closely veined than the wings of dragon flies? (Fig. 177.) For an interesting account of the order “Joined-wings” (bees and their kindred) see Comstock’s “Ways of the Six-footed,” Ginn & Co. =Illustrated Study of Beetles.= [Illustration: FIG. 162.--Diving beetle (_Dysticus_), with larva, _a_.] [Illustration: FIG. 163.--Weevil.] [Illustration: FIG. 164.] [Illustration: FIG. 165.] [Illustration: FIG. 166.--Click beetle.] [Illustration: FIG. 167.--MAY BEETLE.] [Illustration: FIG. 168.] [Illustration: FIG. 169.--Colorado beetle (potato bug).] =Illustrated Study of Beetles= (Figs. 162-169).--Write the life history of the _Colorado beetle_, or potato bug (Fig. 169), stating where the eggs are laid and describing the form and activities of each stage (the pupal stage, _b_, is passed in the ground). Do the same for the MAY BEETLE (Figs. 167-168). (It is a larva--the white grub--for three years; hogs root them up.) Beetles, like moths, may be trapped with a lantern set above a tub of water. Where does a _Scarab_ or sacred beetle of the Egyptians, also called tumble bug (Fig. 164), lay its eggs (Fig. 165)? Why? How does the _click beetle_, or jack snapper (Fig. 166), throw itself into the air? For what purpose? The large proboscis of the _weevil_ (Fig. 163) is used for piercing a hole in which an egg is laid in grain of corn, boll of cotton, acorn, chestnut, plum, etc. How are the legs and body of the _diving beetle_ suited for swimming (Fig. 162)? Describe its larva. What is the shape of the lady bug (Fig. 97)? It feeds upon plant lice (Fig. 185). Is any beetle of benefit to man? [Illustration: FIG. 170.--Life history of ant lion.] =Illustrated Study of Ant Lion, or Doodle Bug= (Fig. 170).--Find the pitfall (what shape?); the larva (describe it); the pupa case (ball covered with web and sand); the imago. Compare imago with dragon fly (Fig. 177). How does ant lion prevent ant from climbing out of pitfall (see Fig. 170)? What is on edge of nearest pitfall? Explain. Ant lions may be kept in a box half filled with sand and fed on ants. How is the pitfall dug? What part of ant is eaten? How is unused food removed? How long is it in the larval state? Pupal state? Keep net over box to prevent adult from flying away when it emerges. [Illustration: FIG. 171.] [Illustration: FIG. 172.--Metamorphosis of house fly (enlarged).] [Illustration: FIG. 173.--Metamorphosis of flea.] [Illustration: FIG. 174.--Louse.]