It's not dangerous. In fact, it's actually good for them! Turtles swallow small stones to aid their digestion. The stones help grind up the food in their stomachs. Turtles only have a beak-like mouth to help them break their food into smaller pieces. Since they don't have teeth and saliva to help break down the food before it reaches their stomachs, when it reaches their stomachs it is practically whole.
There are other reasons they might swallow stones, too (see the Related Link). I always thought my turtles were just really stupid, and were swallowing the stones because they thought they were food. Not so!
The red ear slider terrapin lives up to 50 years
I wouldn't recommend it.
yes
Yes, they have internal ear structures. They are sensitive to vibration and sound.
Yes you can, they are both variations of the same type of turtle. Just the same you can breed them to the albino.
do you a awser for me
no
Not good....
No creature can survive without food. It may reduce the amount of food it eats during hibernation, but it cannot stop eating altogether.
up to ten inches
yes
i don't think they sleep