I'm so sorry to hear about Snickers. We recently went through the same thing with out cat, Midget. I had Midget before my son was born, and then when Romo was born, Midget became his cat. She would sleep in front his crib or door and growl, literally growl, at anybody who walked by the door. Romo was the only one who could walk her on her leash (she had one for a little bit cause we had to move). If Romo was gone for the weekend at his dad's house Midget would hide under his bed until he got home and then come running through the house at the sound of his voice. They were adorable together. Every morning, Romo would let Midget outside while we got ready and then before we left he would call out to her and she would come running back inside. One Sunday, we let her out and since we were home we didn't call her back right away. And then she never came back. We hung posters and called all animal shelters in our area. And then a few days passed and a neighbor about 3 houses up called and said she saw or cat get attacked by a coyote in her front yard the day my cat went missing. She tried to stop it but wasn't going to go outside with the coyote and I can't really blame her for that. Telling my son that Midget wasn't coming home was tough. He had already dealt with death, as his Nana (great grandmother) had passed away the year before and his Grandpa had passed away before that. We had told him that his grandparents were stars, and at night we go outside and he points out which one is Nana and Grandpa and now which one is Midget and we talk to them. He knows that Nana and Grandpa are taking care of Midget now and it seems to help him. He was almost 5 when Midget was killed, Midget was 14. He still talks about her, and sometimes gets confused when he sees an orange cat and says Mommy Midget came home and I have to remind him that she can't come home, but we can play with her in our dreams and we can talk to her when she turns her night light on (her star). I hope this helps. It's so hard telling your kids something like this whether it be a pet or family member. Take care!
H.