A five gallon bucket with 6" or so of water works good. Check it often. Put it in the floor board.

I keep water in my mop bucket and find them in there sometimes.

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.