  The radiation emitted by horizonless exotic compact objects (ECOs), such as
wormholes, 2-2-holes, fuzzballs, gravastars, boson stars, collapsed polymers,
superspinars etc., is expected to be strongly suppressed when compared to the
radiation of black holes. If large primordial curvature fluctuations collapse
into such objects instead of black holes, they do not evaporate or evaporate
much slower than black holes and could thus constitute all of the dark matter
with masses below $M < 10^{-16}M_\odot.$ We reevaluate the relevant
experimental constraints for light ECOs in this mass range and show that very
large new parameter space down to ECO masses $M\sim 10\,{\rm TeV}$ opens up for
light primordial dark matter. A new dedicated experimental program is needed to
test this mass range of primordial dark matter.
