File:Lethal-Fighting-in-Nematodes-Is-Dependent-on-Developmental-Pathway-Male-Male-Fighting-in-the-pone.0089385.s002.ogv

English: Headgrab. This movie opens with two males moving normally. After about a minute, one male wraps its tail around the anterior end of the other male and coils tightly. Initially, the victim thrashes strongly as if to gain release, but within 30 seconds has almost ceased moving. The victor unwinds partly and briefly touches the victim's tail with its head, as if to check that it is incapacitated. It then fully releases its hold. The victor contacts the victim again several times. The victim remains largely inactive and abnormally bent at both head and tail ends.