Do neutrinos have a half-life? I know that neutrons are stable within the nucleus of an atom but free neutrons have a half-life. I couldn't find any information on neutrino half-lives.
Do neutrinos have a half-life? Since neutrinos are rarely measurable, do we have enough information to know?
 A: Neutrinos are elementary particles in the standard model, which model has been very successful in organizing all the data we have on elementary particle interactions in a mathematically rigorous form. In the table for elementary particles neutrinos are considered stable, in contrast to taus and muons, as quantum  number and energy conservation, within the standard model hypothesis, do not allow them to decay. Thus we trust that neutrinos do not decay, otherwise the calculations would not fit the data we have on neutrinos, as they do. If they are found to decay that would show the need for a theory  beyond the standard model.
Still, as CuriousOne says in the comments, there are experiments trying to find limits for neutrino decays, which are very small, and do not challenge the standard model at the moment.
Neutrinos can disappear in interactions with other elementary particles, but the timing depends on the specific interactions. They can also oscillate within the species of neutrinos, this also has been measured and slotted into the standard model, but that is a different story than decay.
