Where do you draw the line on who can have rights? Do insects have rights?

Generally we draw the line at sentience. A sentient being is one that has interests of its own and this is considered necessary for being part of the moral community.

We don’t know whether insects are sentient, although it could be argued that they are. However just because we don’t know whether insects are sentient doesn’t relieve us of the responsibility towards animals that we do know are sentient. This question is generally meant to illustrate that where to draw the line is a matter of opinion, or that if it is too difficult to decide where to draw the line, just don’t draw one at all. If we do draw a line at sentience then we acknowledge the right for sentient beings to have lives outside of human interests.