  We entertain the possibility that scalar leptoquarks (LQs) generate
consequential effects on the strangeness-changing decays of hyperons and kaons
involving missing energy carried away by a pair of invisible fermions. Although
such processes have suppressed rates in the standard model (SM), they could get
significant enhancement in the presence of the LQs. In order to respect the
available data on the kaon modes $K\to\pi\nu\bar\nu$ and increase the rates of
the hyperon decays substantially at the same time, two different scalar LQs are
needed. If the LQs have Yukawa couplings solely to SM fermions, we find that
the hyperon rates cannot attain values within the reach of ongoing or
near-future experiments because of the combined constraints from the
measurements on kaon mixing and lepton-flavor-violating processes. However, if
we include light right-handed neutrinos in the LQ interactions, their
contributions can evade the leading restrictions and translate into hyperon
rates which may be big enough to be probed by upcoming searches. Thus, these
hyperon modes could provide a new avenue for seeking sterile neutrinos.
