That is what males do, unless you have a very big enclosure he will torment the poor female forever. Remember in the wild he would only encounter a female every so often, so right now he probably thinks he is in heaven.
He thinks it's mating time, the males tend to be a bit of a bully when they get the urge and the female shuns him, he will ram her to the extent of damaging her shell.
If he is larger than her put a small hide in that only she can get into, if not then like DMMJ said get a bigger enclosure or separate them.
It can be quite stressfull for a female, that's why I have more females than males...
Yep, DMMJ is totally correct. A male Horsefeild will harass a female to death if he has the opportunity to do that. You need to separate them for her sake
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Its hard to keep a pair of Russian tortoises in the house. If you have a large outdoor pen, she can usually find a place out of his sight and its easier on the pair, but in the house in a small habitat, pairs just don't work out.
my female is a lot bigger than my male and thank you for your answers as they have helped me a great deal and i will separate them as don't want MIA affected by oscars bulling antics