Wikipedia
Micropezidae
The Micropezidae are a moderate-sized family of acalyptrate muscoid flies in the insect order Diptera, comprising about 500 species in about 50 genera and five subfamilies worldwide, (except New Zealand and Macquarie Island). They are most diverse in tropical and subtropical habitats, especially in the Neotropical Region.
Insects in this family are commonly called stilt-legged flies, after their characteristically long legs. The fore legs are markedly smaller than the other pairs. Mostly, they are long-bodied, often black flies, usually with infuscated (darkened) wings. Wings are reduced in the genera Calycopteryx and entirely absent in the ant-like Badisis ambulans.