They seemed like it was on one side. You put them on their feet, and they just fell. Almost like one side was, like, paralyzed. Reporter there was no sign of people feeding birds and no sign of poisoning. So Inspectional Services is checking to see if anyone used a control agent called avatrol. There are three types of birds you can do control measures on. You can use a chemical called avatrol. It has to be mixed in a very safe way, not its made to disperse. It is a shocking agent. Reporter no other species of birds were affected, only the grackles which are only ash here in the summer. So the Animal Rescue league of boston and Inspectional Services are trying to figure it all out. Were not sure whats going on if there is an environmental toxin or some disease thats being spread around the birds. Reporter you heard Inspectional Services mention avatrol. To use it, you have to have a permit. To figure out if anyone in the area has a permit for that. Reporting live from dorchester, im bi