Someone said a canard wing is more prone to icing than a stabilizer. If true, what would explain this?
It has to do with the local speed around the airfoil.
In a canard configuration, the forward wing has to produce more lift per area than the main wing in order to have natural longitudinal (or pitch) stability. This means the suction is more intense, and the pressure on the upper side of the airfoil right behind the leading edge is lower than on the main wing. Also, the angle of attack of the wing is higher, presenting a larger area to the oncoming flow. Large droplets of supercooled water will simply splash on the leading edge and freeze there instantly, causing clear icing.
In a conventional aircraft the tail surface will provide very little lift, and in many cases even produces a small downforce. Now the main wing shows lower pressure on the forward part of the airfoil, just where ice collects the most. In the special case where the tailplane is in the wake of the wing, some of the water droplets will have frozen to the wing already and less water will be available to cause tailplane icing.
The capacity of air to hold water depends not only on temperature, but also on pressure: The lower the pressure, the more likely it is for condensation to happen. Condensed, super-cooled water, or liquid water hitting a cool surface, will form ice. Now you have both components needed for the explanation.
Pitch stability is the explanation for the higher propensity of canard wings to collect ice than conventional tailplanes!
If the canard has a thinner leading edge compared to the stabilizer, this could happen. From BEA Systems Think Ice:
A relatively large radius aerofoil at moderate or low airspeed creates a larger pressure wave ahead of the leading edge, which forces the air around it, carrying most of the moisture with it. Only droplets sufficiently heavy to overcome this flow will impact on the leading edge. Thus, a large chord aerofoil with a blunt leading edge has low ice accretion efficiency. Conversely, a narrow radius leading edge generates a smaller pressure wave and so the accretion rate is greater.
Note that by the same token, the stabilizer is more prone to icing compared to the main wing.