Qmark Electric baseboard heaters and Cadet Electric baseboard heaters contain a sheathed electric heating element completely immersed in a heat transfer liquid and sealed in a heater-length copper tube. This maximizes the volume of heat storage fluid to prolong the thermal constant of the entire heater.
The strongest animal on Earth is the blue whale. The blue whale is also the largest creature in the entire world.
If you're asking for the strongest animal in the world, in literal terms it's going to be a huge animal, probably the blue whale (which is the biggest animal that has ever lived). If you mean strongest in terms of its size, it will be an insect, probably some species of ant or beetle.