In ceramic La1-xCaxMnO3 samples with 0⩽x⩽0.15 and the concentration of holes c = 0.18-0.22 between T = 77 and 340 K the resistivity, ρ, is shown to have an activatedcharacter both above and below the ferromagnetic Curie temperature,TC. The temperature dependence of the local activation energy,Eloc (T) = dln ρ(T)/d(kT)-1 givesevidence for a variable-range hopping conductivity over states ofthe Coulomb gap. The width of the gap Δ≈0.24 eV, theeffective dielectric permeability κ≈3.6 and thecarrier localization radius ξ≈5.1 Å in theparamagnetic phase are determined. The value of ξ suggestshopping of small lattice polarons at T>TC. With decreasingtemperature two successive transitions, at temperatures TC' andTC'', associated with divergence of the correlation length, areobserved in the vicinity of TC. They can be interpreted interms of critical increase (as T approaches TC' from highertemperatures) and decrease (when T shifts from TC'' towardslower temperatures) of the radius of magnetic polarons, generated bya small fraction of the lattice polarons as T→TC. Thedifference between TC and the temperature of the firstdivergence of ξ, TC'<TC, gives evidence of percolativecharacter of the FM-PM transition.