Our tadpoles have transparent skin on the outside of their body. If you look closely you will see their clear skin puffing up when they swim really fast and you might see their heart pumping. Most tadpoles like to "play dead" in the water. Usually when they are scared they do this. You might see them digging the gravel.
That same day we got our two African- Clawed Tadpoles. You might see something golden which is their heart. One day one of the tadpoles finally discovered the tunnel in their "mansion like" tank and they were hiding in it.
These were some behaviors of our amazing Bufo Americanus and African- Clawed Frog tadpoles.