.... Kids father

Well i just got a very ugly phone call from my ex spouse stating that he was going to bring the cops to my parents house because my parents watch them while i work and take the kids away while im at work and he has every right to do so cause hes the father and their the grandparents. We have no agreement and im still waiting to go to court with this man for child support/visitation. Its the stupidest thing ive heard and doubt its true. He just rubs me the wrong way threatning me hes going to take my kids away....while hes the one who left us! Has anybody dealt with this. Oh and we live in Texas. -Tia