Matthew Cobb on bees who die when they sting:
The explanation for this behaviour is that the bee is protecting its hive, and thereby its genes. Worker bees are generally sterile (though they can produce male eggs under certain circumstances), so the only way it can make a genetic contribution to the next generation is by helping the hive, with which it shares a high proportion of its genes.
From a gene’s eye view, this is not suicide at all, but merely the death of one carrier of those genes, to preserve the life of many more carriers. So apart from the examples of social insects, DO animals commit suicide?