A crawling wonder on back!

At school, as boys we used to play on its sandy ground. Then we were often stunned by feeling some creature crawling up between our shirt and the back. As soon as we understood it to be a 'biting ant' we pulled out our shirts and brushed away this ant - to avoid its agonizing bite. Yes, this is a special type of 'ant' that looks like an ant; but it is a different one: a Flightless Wasp! (Eupelmus vesicularis, 'Rail vandi erumbu, Soogai erumbu' in Tamil).