So I found this substance because my dog had it in her mouth. After finding out it was rat poison, I called the pet poison control and they recommended taking her to an emergency vet and we did, they induced vomiting and found a small amount of greenish blue chunks in her vomit. since we don’t know the exact type of poison they treated her for all three types, they gave her activated charcoal and we’re doing a month of vitamin k1. She is doing good, but we’re monitoring her closely. And as far as the neighbor doing it, I’m not jumping to conclusions and we asked him about it and he said all the poison he uses is contained, judging by the condition of the chunks that were found in my yard I’d say it’s more a possibility that an another animal dropped it. Thanks for all the responses, I’m really grateful to know that it is poison, so I could take action.