Would the grub killer harm the birds if they eat the grubs?

Usually birds will stay away from grubs if they are dead from killer

if there was arecent rain that may explain the dead worms

don't worry try to trap the mole in a have a heart trap the grub killer wont hurt birds as they avoid it

Grubs Killer

Yes the grub killer also does in worms. Sorry, but then the moles are also eating worms. As for birds, you'd assume the bird was digging down deep enough to get the grubs. Maybe. Are you sure this was the best time for grub control? Here it is the worst as the grubs are big and about ready to pupate into beetles and the like and are nearly impervious to grub control. Here we use the grub control in late summer/early fall when the grubs are smaller, more easily killed.

Depends on the grub species as to when to apply control. Advertisers don't specify which species are best killed when, they just want to sell the product. Best to ask your Cooperative Extension Service horticulture agent, not the nurseries who want to sell you product.

Bald eagles almost became extinct because of the use of DDT to control insects. At one time the Bald Eagle population was down to 500 pairs in the entire USA. Thankfully, through strict enforcement of Eagle protection laws, the Bald Eagles have recovered from the edge of extinction.

The DDT was passed up the food chain through animals that ate bugs and then were ate by the Eagles.

So yes, birds can be harmed by eating animals killed by poison.

I don't know your particulars exactly but I know if I put out poison for rats and mice and a cat eats them, the cat is poisoned too. Birds are easily poisoned so I would be very very careful. I don't know about worms.

I do not know I have never herd of that befor but one time I put out some gofer bait and killed a lot of birds I felt so bad for them I spilled them and did not pick them up and I killed some squrills I think.