My cat licked ant poison (Terro/borax), is lethargic, not vomiting.

I would recommend that you call ASPCA's poison control number. That number is 888-426-4435. There is a $65 charge, but they will be able to best advise you. Please have the label available so you can let them know the type of poison listed, and what any other potentially concerning ingredients were. 

Borax is toxic to cats and you can see vomiting, diarrhea, stomach pain, and excessive thirst. This really does have to be checked out by a vet immediately, and emergency vets should be open all night. Please take Rocket Girl into an ER vet clinic; if there isn't one in your area, there will be a vet on call for emergencies. The information to reach that vet is found on a clinic's answering machine or website.

Borax is toxic to cats, and while it it low on the toxicity scale, if Sweet drank some borax, it's best that she is seen by a vet now. Symptoms of borax toxicity include diarrhea and vomiting to muscle weakness and seizures, and are usually seen shortly after ingestion. I would take Sweet into an ER vet or find vet on call to see her now.

Because Blue only licked it so briefly, I would not rush her into a vet. You may see some drooling and frothing at mouth. I would rinse out her mouth with cool water using a syringe, and keep an eye on her. If she does start acting out of the ordinary, starts having uncoordinated movements, tremors, convulsions, or seizures, I would take her into a vet immediately.

I'm sorry to hear about the loss of your cat! How awful. It's very unlikely that the ant traps would have had anything at all to do this with this - borax is fairly non-toxic, and would require ingestion of a really large amount in order to cause any serious problems. Exposure to traces of it from simply being in the same area as the traps should not cause any issues at all. Again, I'm very sorry for the loss of your kitty.

I would recommend that you have Sampson examined by a vet as soon as possible. The vet may recommend that you call the pet poison helpline to determine if there is a toxic exposure to the Hotshot chemical. There can be many other causes of lethargy and poor appetite, such as kidney disease, diabetes, pancreatitis, etc. and the vet may need to start with some blood work or x-rays after they do the physical exam to determine what could be going on.

It can be scary when there's a possibility your cat is sick! Lethargy is seen as a cat acting very tired, not wanting to move much, little interest in getting pet, sleeping a lot more than normal. Personally in my opinion, I always thinks it's best to be safe than sorry, and if you'd feel better taking her into the vet, that's absolutely fine! You may rest easier knowing everything is ok with her, and if she does seem a little tired, a vet visit may be a good idea. Otherwise, keep watch on her for the signs mentioned by the expert in your previous question. I hope this helps!