The first one is a "true bug", order Hemiptera, suborder Heteroptera. The most obvious diagnostic feature is the X structure formed by the front wings when held flat over the back. This shape results from each wing being divided into a membranous outer section and a thickened basal section, combined with a triangular plate that is part of the thorax. The triangular plate forms the bottom quarter of the X, the thickened basal sections of the wings form the side quarters, and the membranous outer sections, overlapped, form the top quarter.
The second is a "true fly", order Diptera. The diagnostic features are two wings and two halteres, the latter seen in your specimen as those white lumps shaped like punching bags, positioned between the middle and rear legs. A flying ant would have four wings.
