  Proton-proton (pp) collisions have been used extensively as a reference for
the study of interactions of larger colliding systems at the LHC. Recent
measurements performed in high-multiplicity pp and proton-lead (p-Pb)
collisions have shown features that are reminiscent of those observed in
lead-lead (Pb-Pb) collisions. In this context, the study of identified particle
spectra and yields as a function of multiplicity is a key tool for the
understanding of similarities and differences between small and large systems.
We report on the production of pions, kaons, protons, $K^{0}_{\rm S}$,
$\Lambda$, $\Xi$, $\Omega$ and $K^{*0}$ as a function of multiplicity in pp
collisions at $\sqrt{s}=$ 7 TeV measured with the ALICE experiment. The work
presented here represents the most comprehensive set of results on identified
particle production in pp collisions at the LHC. Spectral shapes, studied both
for individual particles and via particle ratios as a function of $p_{\rm T}$,
exhibit an evolution with charged particle multiplicity that is similar to the
one observed in larger systems. In addition, results on the production of light
flavour hadrons in pp collisions at $\sqrt{s}=$ 13 TeV, the highest
centre-of-mass energy ever reached in the laboratory, are also presented and
compared with previous, lower energy results.
