Abu Hurairah (May Allah be pleased with him) reported:
The Messenger of Allah (ﷺ) said, "The martyr experiences no more pain in being slain than one of you experiences from the stinging of an ant."[At-Tirmidhi]. (IT)
App reference (IT): Book 12, Hadith 39 (IT)
Arabic/English book reference (IT): Book 12, Hadith 1323 (IT)